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Volume 51 (2021): Issue 4 (December 2021)

Volume 51 (2021): Issue 3 (October 2021)

Volume 51 (2021): Issue 2 (June 2021)

Volume 51 (2021): Issue 1 (March 2021)

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Volume 50 (2020): Issue 1 (March 2020)

Volume 49 (2019): Issue 4 (December 2019)

Volume 49 (2019): Issue 3 (October 2019)

Volume 49 (2019): Issue 2 (June 2019)

Volume 49 (2019): Issue 1 (March 2019)

Volume 48 (2018): Issue 1 (December 2018)

Volume 47 (2018): Issue 1 (December 2018)

Volume 46 (2018): Issue 1 (June 2018)

Volume 45 (2018): Issue 1 (March 2018)

Volume 44 (2017): Issue 1 (December 2017)

Volume 43 (2017): Issue 1 (October 2017)

Volume 42 (2017): Issue 1 (June 2017)

Volume 41 (2017): Issue 1 (March 2017)

Volume 40 (2016): Issue 1 (December 2016)

Volume 39 (2016): Issue 1 (October 2016)

Volume 38 (2016): Issue 1 (October 2016)

Volume 37 (2016): Issue 1 (July 2016)

Volume 36 (2015): Issue 1 (December 2015)

Volume 35 (2015): Issue 1 (November 2015)

Volume 34 (2015): Issue 1 (September 2015)

Volume 33 (2015): Issue 1 (September 2015)

Volume 32 (2014): Issue 1 (December 2014)

Volume 31 (2014): Issue 1 (September 2014)

Volume 30 (2014): Issue 1 (June 2014)

Volume 29 (2014): Issue 1 (March 2014)

Volume 27 (2014): Issue 1 (February 2014)

Volume 26 (2013): Issue 1 (June 2013)

Volume 25 (2013): Issue 1 (March 2013)

Volume 24 (2012): Issue 1 (December 2012)

Volume 23 (2012): Issue 1 (September 2012)

Volume 22 (2012): Issue 1 (June 2012)

Volume 21 (2012): Issue 1 (March 2012)

Volume 20 (2012): Issue 1 (January 2012)

Volume 14-15 (2010): Issue 2010 (December 2010)

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Volume 8 (2008): Issue 1 (December 2008)

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Volume 6 (2008): Issue 3 (September 2008)

Volume 5 (2008): Issue 2 (June 2008)

Volume 4 (2008): Issue 1 (March 2008)

Volume 3 (2007): Issue 2007 (January 2007)

Journal Details
Format
Journal
eISSN
2083-4608
First Published
26 Feb 2008
Publication timeframe
4 times per year
Languages
English

Search

Volume 48 (2018): Issue 1 (December 2018)

Journal Details
Format
Journal
eISSN
2083-4608
First Published
26 Feb 2008
Publication timeframe
4 times per year
Languages
English

Search

27 Articles
Open Access

Analysis of aerodynamics and main rotor loads under stalled conditions of helicopter’s main rotor during the pull-up manoeuvre

Published Online: 29 Mar 2019
Page range: 7 - 29

Abstract

Abstract

The article discusses the main features of the applied simulation model of helicopter flight indicating references, where it was elaborated in detail. It focuses on presenting the simulation results of pull-up manoeuvre during which the helicopter does not respond correctly. The reasons for the behaviour as mentioned above were explained based on the results of calculations. The capabilities of the simulation model were used to determine the current loads of particular blades of the helicopter’s main rotor. The results were illustrated by maps of the angles of attack and aerodynamic lift on the surface of the main rotor and the distributions of these parameters along blades on characteristic azimuth for individual manoeuvre phases.

Keywords

  • pull-up manoeuvre
  • simulation
Open Access

Durability of airfield pavement cement concrete in the presence of de-icing agents

Published Online: 29 Mar 2019
Page range: 31 - 53

Abstract

Abstract

In Poland the climatic conditions in the autumn and winter season are particularly severe for concrete infrastructure. Concrete’s resistance to frost and chemical deicing agents determine the durability of cement concrete pavement. An increase in the premature deterioration of airfield pavements exposed to new generation deicing chemicals may suggest that there is a relation between the damages and the application of the deicers. The paper presents selected results of microstructural analysis of the airfield pavements concrete exposed to the deicers based on acetates and formates. Microscopic evaluation was carried out with the scanning electron microscope (SEM). The local chemical compositions of the phases of interest were performed using the Energy Dispersive X-ray analysis (EDX).

Keywords

  • airfield pavements
  • cement concrete
  • de-icing agents
  • microstructure
Open Access

Alternative fuel in the combustion process of combustion engines

Published Online: 29 Mar 2019
Page range: 55 - 81

Abstract

Abstract

The article analyses the impact of emulsified fuel, containing H2O2 hydrogen peroxide, on the emissions of nitrogen oxides and diesel engine smoke. The process of forming toxic components in exhaust gases of reciprocating engines during the engine operation, and the relationship that specifies the hydrogen peroxide decomposition process were presented. The research was carried out with the use of fuel containing 30%, 20% and 10% of hydrogen peroxide. The concentration courses of the nitric oxide (NO) and nitrogen oxides (NOx), as well as the (CO) carbon monoxide concentration and (S) engine smoke courses were shown separately for the external characteristics of the engine. Finally, the importance of knowledge related to the mechanisms of generation of toxic components in exhaust gases in the reciprocating engines was emphasised.

Keywords

  • combustion engines
  • air pollution
  • environmental protection
Open Access

Fatigue tests, self-healing of polymer-matrix composites in unmanned aerial vehicles

Published Online: 29 Mar 2019
Page range: 83 - 106

Abstract

Abstract

This publication presented the main issues related to fatigue of polymer composite materials. It was featured a fatigue stress test based on composite sample, made of carbon fiber-reinforced polymer, using the four-point bending method. The test was carried out with the initial load and using positive load cycles. The perspectives of diagnostics and self-healing of composite materials, including intelligent materials, were also presented.

Keywords

  • fatigue
  • polymer-matrix composites
  • self-healing
  • intelligent materials
Open Access

Investigations of the susceptibility of unmanned aerial vehicles on intensive microwave radiation

Published Online: 29 Mar 2019
Page range: 107 - 118

Abstract

Abstract

Commercially available drone type unmanned aerial vehicles (UAV), as well as parts and subsystems enabling the assemble of UAVs, are becoming more and more widely available, and their performance is constantly improving. The current possibilities of a drone assembled by a hobbyist predispose are not only to be used as a reconnaissance tool but also as a guided missile. The use of a camera with a video stream transmitter simultaneously with virtual reality goggles and video stream receiver gives the pilot an impression of being on the drone, which makes it possible to control it with extreme precision, even at high speeds. The article presents research aimed at determining the extent and type of damage made on exemplary racer drone caused by intense microwave field radiations.

Keywords

  • unmanned aerial vehicles (UAV)
  • drone
  • HPM
  • EM radiation susceptibility
Open Access

Modelling the flight dynamics of aerial target imitator

Published Online: 29 Mar 2019
Page range: 119 - 147

Abstract

Abstract

This article is concerned with the issue related to studying the dynamic properties of the aerial target imitator. Applying the modelling principles, the structure and technical data of aerial target imitator were described and utilising the PRODAS software a physical model of the aerial imitator was developed based on the conducted simulation studies. Mass, aerodynamic and basic parameters of flight path were determined. Then, experimental studies of basic dynamic characteristics were discussed. The comparison of results obtained from experimental and theoretical studies proves the correctness of the developed model.

Keywords

  • flight dynamics
  • ballistics
  • modelling
  • aerial target imitator
Open Access

Procedures concerning preparations of autonomous underwater systems to operation focused on detection, classification and identification of mine like objects and ammunition

Published Online: 29 Mar 2019
Page range: 149 - 168

Abstract

Abstract

The article presented below is a prelude to the process of conducting sea bottom researches with autonomous underwater systems, focused on detection, classification and identification of objects causing possible threat for shipping and maritime environment. An article include guidelines and suggestions for the operators of autonomous underwater vehicles (AUV), mainly concerning preparations for the operation.

Keywords

  • sonar technologies
  • sea bottom researches
  • autonomous underwater systems
Open Access

Evaluation of the possibilities to use imagery reconnaissance sensors to identify the geological-engineering conditions in lowland river channels

Published Online: 29 Mar 2019
Page range: 169 - 189

Abstract

Abstract

The article concerns the issue of using imagery reconnaissance sensors for the identification of geological-engineering conditions in river channels, in the aspect of evaluating the forcing of a water obstacle. It discusses the issues associated with using air platforms (manned and unmanned) in remote sensing surveying of selected fragments of the Vistula and Bug river channels and the correct interpretation of the obtained results, through their verification using bathymetric tests conducted directly in the river channels.

Keywords

  • remote sensing
  • bathymetric measurements
  • imagery reconnaissance
  • morphodynamics
  • lithology
  • imagery reconnaissance sensors
Open Access

Opportunities and barriers regarding the development of selected methods for obtaining hydrogen from bioethanol

Published Online: 29 Mar 2019
Page range: 191 - 222

Abstract

Abstract

The development of the commercial air carriers market causes an increase in the aviation fuel consumption and the air pollution. There are intensive works in order to invent the possibility of supplying the aviation engines with biofuels. The hydrogen gas is needed for technological processes to obtain the synthetic biocomponents from biomass, which met the quality standards for fuels and aviation fuels. Pure hydrogen gas is scarce in the Earth’s atmosphere and has to be derived from petroleum products. Its acquisition currently requires the processing of petroleum-based matter. The whole world is looking for easy, cheap and safe ways of producing hydrogen from a variety of renewable raw materials, that are an alternative to fossil fuels. The article shows the technological potential of experimental methods for hydrogen production from ethanol produced from biodegradable waste, which is widely considered as a renewable and environmentally friendly resource.

Keywords

  • aviation fuels
  • biofuels
  • producing hydrogen from renewable raw materials
Open Access

Critical physicochemical properties of lubricating oils for aviation applications and their significance in terms of flight safety

Published Online: 29 Mar 2019
Page range: 223 - 251

Abstract

Abstract

The article presents the role of lubricating oils for aviation applications, along with their classification, and discusses the key physicochemical properties. It characterises engine, transmission gear, hydraulic and instrumentation oils and their impact on a device operational reliability. It also points out the requirements for these products in relation to the operating conditions and the chemical composition of a product.

Keywords

  • lubricating oils
  • physicochemical properties
  • safety
Open Access

The impact of microstructural non-conformities on microhardness of EN AW 5754 aluminium alloy welded joints made with the use of the TIG method

Published Online: 29 Mar 2019
Page range: 253 - 262

Abstract

Abstract

The article presents the impact of welding non-conformities on microhardness of EN AW 5754 aluminium alloy welded joints made with the use of the TIG method. The results of microhardness tests of welded samples made with various process parameters. The impact of the welding non-conformities disclosed with the use of a tomographic method on the welded joint microhardness were analysed. The studies showed a strong link between the participation of welding non-conformities, welding process parameters and microhardness of welds.

Keywords

  • aluminium alloy
  • weld
  • microstructure
  • non-conformities
  • microhardness
Open Access

Polish experience from the operation of helicopters under harsh conditions

Published Online: 29 Mar 2019
Page range: 263 - 299

Abstract

Abstract

The result of operating the military helicopters in a dusty environment is a loss of performance and premature failures of gas paths of the engines. The efficient protection of the power plant against dust ingestion is tough, especially in the desert. The article summarises the experience accumulated while operating the military helicopters under harsh conditions in Poland and during foreign missions. There were characterised the types of conducted missions, operated helicopters, protection methods of engines and common failures. It was stated that the performance of TV3-117 engines and their particle separation systems was insufficient in the mountains and on the desert (Iraq and Afghanistan). The deterioration of gas paths resulted in the loss of helicopters’ performance and substantially contributed to the few aircraft incidents. The experience gained during foreign missions is used in training the crews and ground personnel and in the programmes of modernisation and renewal of the helicopter fleet.

Keywords

  • dustiness
  • blades
  • engine deterioration
  • turboshaft PZL-10W
  • helicopter
Open Access

Influence of source data on fatigue estimation of a fighter aircraft

Published Online: 29 Mar 2019
Page range: 301 - 322

Abstract

Abstract

Aircraft structures during operation are exposed to fluctuating loads caused both by aerodynamic and inertial loads. This fluctuation leads to the creation of fatigue cycles, which gradually diminish the residual durability of the structure. During the design process, the flight envelope is defined as well as the design load spectrum, which then defines the durability of the structure (often expressed in means of flight hours). However, during the operation of an individual aircraft the actual load cycles can be significantly lower or higher than the designed; therefore, load monitoring is essential for safe operation of aircraft structures.

The following article shows the results of fatigue analysis based on flight data from different flight data recorders for the Su-22 fighter aircraft.

Keywords

  • aircraft fatigue
  • flight data acquisition
  • load monitoring
Open Access

Prototype of the expert tribological diagnostic system of turbine engine

Published Online: 29 Mar 2019
Page range: 323 - 340

Abstract

Abstract

The article presents issues related to the construction of a prototype of an expert tribological diagnostic system for a turbine engine. The database consists of the results of tests on the chemical composition and concentration of the wear products in the oil sample as well as the physico-chemical parameters of the oil. For all diagnostic parameters, threshold values have been defined to classify the level of wear (normal, elevated, increased and emergency). PC Shell software enabling the combination of a rule representation of knowledge and procedural programming was used to build the expert system. The computer application consists of the main module and sources of knowledge dedicated to the applied research methods. The modular structure allows the development of an expert system by adding new research methods.

Keywords

  • turbine engine
  • tribological diagnostics
  • expert diagnostic system
Open Access

An expert system aided method of the blade vibration sources identification with blade-tip timing (BTT) signal decomposition

Published Online: 29 Mar 2019
Page range: 341 - 358

Abstract

Abstract

An expert system aided method of the blade-tip signal decomposition to the turbine blade vibration sources identification is presented. The method utilises a multi-valued diagnostic model based on the discrete wavelet transform. Proposed algorithm consists of four stages: signal decomposition into low- and high-frequency components (approximations and details), approximations and details parameterization, multi-valued encoding of parameters obtained at the second stage, an expert system use of the turbine blade vibration sources identification.

Keywords

  • blade-tip timing
  • multi-valued diagnostic-decision model
  • wavelet transform
  • signal parameterization
  • multi-valued encoding
Open Access

Electrical supply of aircraft during parking

Published Online: 29 Mar 2019
Page range: 359 - 370

Abstract

Abstract

The elaboration discusses selected aspects of parking supply of aircraft with electricity generated by mobile, airfield sources. In terms of sublime electrical and electronic systems, as well as avionic systems installed on-board of contemporary aircraft, the quality of electricity supplied by ground sources results in their manufacturers facing with high requirements that are contained in relevant standards and regulations. The quality of electricity generated by ground sources and their compatibility have a direct impact, among others, on the calibration of aircraft avionics systems during the ground flight preparation, which directly contributes to the safety of air operations. Therefore, the possibility of constant real-time monitoring of the supplied electricity (specific parameters) enabling immediate identification, recording, adjusting the deviations, hence, preventing damage or improper preparation of an aircraft for flight, becomes a non-trivial issue.

Keywords

  • power supply of aircraft on the ground
  • mobile power devices
  • GPU
Open Access

Hydraulic plunger pump contamination sensitivity evaluation

Published Online: 29 Mar 2019
Page range: 371 - 383

Abstract

Abstract

The correct operation of the hydraulic pump and achieving the assumed durability depends on the purity of the used working fluid. The research paper discusses a method for evaluating the contamination sensitivity of a hydraulic plunger pump. The theoretical grounds for evaluating the contamination sensitivity of hydraulic plunger pumps of a hydraulic drive based on the contamination sensitivity factor were presented. An example of evaluating contamination sensitivity of an NP-34M hydraulic plunger pump was discussed.

Keywords

  • hydraulic drive
  • hydraulic pump
  • working fluid
  • impurities in the liquid
Open Access

Pneumatic propellant system model of an emergency parachute system for a vertical take-off and landing UAV

Published Online: 29 Mar 2019
Page range: 385 - 398

Abstract

Abstract

The subject of this publication is a mathematical model of a pneumatic supply system for an emergency parachute system. This system is intended for a vertical take-off and landing UAV. An overview of emergency parachute landing system designs is presented in the introduction. Based on a schematic diagram and a 3D computer model, the construction and operation principles of an emergency parachute system, currently being developed at AFIT, was presented. A mathematical model, which enables the determination of the energy of gas (compressed CO2) stored in the accumulator tank was described. The conducted tests, which involved weighing the accumulator after filling with liquefied CO2 from a special cartridge and equivalent mass ejections were discussed. These tests involved recording the track of the equivalent mass movement and time necessary to determine velocity. The results of calculations regarding the equivalent mass energy imitating an emergency parachute, CO2 volume and mass in the accumulator in liquefied and gaseous state were presented. Based on the conducted calculations and the obtained characteristics, the developed mathematical model was assessed, and the final conclusions formulated.

Keywords

  • emergency parachute
  • pneumatic accumulator
  • pneumatic energy
Open Access

Towards implementation of a formation flying for efficient UAV operations

Published Online: 29 Mar 2019
Page range: 399 - 417

Abstract

Abstract

A flight of a UAV formation is an efficient way to implement surveillance and reconnaissance operations. The usage of a few UAVs as a formation instead of a single vehicle allows creating a distributed network of sensors, which decreases the duration of flight missions and enlarges a total field of view. From a practical point of view, implementations of formation flights require taking into account several separate aspects of flight of UAV such as a quick take-off of several aircraft, aggregating all UAVs in the same space to create swarm and collective flight of the formation towards the area of a surveillance mission. The paper presents the results of researches and experiments carried out towards practical solutions to those aspects. A magnetic launcher is an excellent appliance to put UAV in the air, and its operation could be repeated quickly. Hence, it is ideal to be used in a formation flight. The leader-follower approach based on two-stage switching control is an effective method to aggregate UAVs in the same space while they are flying over large areas. Whereas, the decentralized control of aerial flocking can be used to achieve a coherent flight of UAV formation, which is able to self-organize. Results from simulations and experiments show the effectiveness of each presented aspect and prove their usability in the implementation of formation flights.

Keywords

  • Unmanned Aerial Vehicles (UAVs)
  • UAVs formation control and flight dynamics
  • UAVs swarm
  • aerial flocking
  • leader-follower control
  • UAVs launching systems
  • magnetic levitation launching systems
Open Access

NATO reqiurements as referred to risk in executed contracts

Published Online: 29 Mar 2019
Page range: 419 - 429

Abstract

Abstract

Requirements on risk management are a problem that is described in all of NATO documents written for contract execution purposes. Namely, these documents have become the basis to introduce these requirements into other documents that apply to various aspects of life.

This article describes problems concerning a risk-based approach in executing contracts for the military.

The core of the documents, developed by the NATO members, has been, since the foundation of these documents, the ISO 9001 standard. Although in the history of the NATO document’s period of validity, they had structure identical to the one of ISO 9000 standard series, in their last iteration they gained their specific structure of contents, oriented for specification of the requirements for contracts execution.

Keywords

  • Risk management
  • contract
  • NATO requirements
Open Access

The structure of recurrent circuits of military aircraft – selected problems based on Su-22

Published Online: 29 Mar 2019
Page range: 431 - 445

Abstract

Abstract

This article comprehensively addresses the problems associated with the structure of recurrent circuits of military aircraft with metal fuselage structure. The authors describe the issues concerning the usage of the fuselage as a recurrent circuit of electric current and with negative conductors connecting the fuselage with negative terminals of the receiver or the source. The military aircraft are frequently operated under harsh conditions of increased humidity, dustiness and variable temperatures. All these factors as mentioned above contribute to the occurrence of intensive electrochemical corrosion at the contact points of airframe’s elements or electrical conductors’ with the fuselage. Such contact surfaces should be subject to monitoring – AFIT has developed the numerous procedures for each aircraft.

Keywords

  • recurrent circuit
  • metallization
  • riveted joint
  • negative conductor
  • neutral conductor
  • stray currents
Open Access

Tribological properties of 3D printed components

Published Online: 29 Mar 2019
Page range: 447 - 463

Abstract

Abstract

Additive manufacturing technology is developing in many industries, including aviation, automotive and others. 3D printing offers new possibilities in the field of designing and manufacturing of machines and devices’ components. The paper presents the results of tribological investigations of components produced in FDM printing technology. The authors presented the evaluation of sliding properties of the model friction couple – block on ring type – of available thermoplastic polymers and polymers’ composites under dry friction conditions. The authors assessed the influence of material type and printed structure on resistance to motion of prepared samples.

Keywords

  • additive manufacturing
  • fused deposition modelling
  • tribology
  • friction coefficient
Open Access

Minimisation of empty runs in transport

Published Online: 29 Mar 2019
Page range: 465 - 491

Abstract

Abstract

The issue of minimisation of empty runs in transport, assumptions and calculation method were presented. The example of ineffective usage of transport means was described as well as a procedure algorithm for the optimisation of the above-mentioned issues using the Solver module.

Keywords

  • transport
  • optimisation
  • minimisation of empty runs in transport
  • Solver module
  • Excel
Open Access

The use of a magnetic flux leakage in the assessment of the technical state of a steel wire rope subjected to bending

Published Online: 29 Mar 2019
Page range: 493 - 513

Abstract

Abstract

The technical state of steel wire ropes has a decisive impact on the safety of people using the equipment in which they are installed. The basis for increasing safety is the ability to assess the condition of the working steel wire. The article presents the use of magnetometric sensors to determine the relationship between the number of steel wire rope bends and its magnetic field induction value. This knowledge, referred to ropes working on real objects, allows to determine the state of stress prevailing in them as well as their condition.

Keywords

  • non-destructive testing
  • magnetic flux leakage
  • steel wire rope
  • bending
Open Access

The mathematical model of the pilot’s ejection process by using the K-36DM ejection seat

Published Online: 29 Mar 2019
Page range: 515 - 541

Abstract

Abstract

The article presents a mathematical model of ejection process, which can be used to analyse the movement of the seat-pilot system in flight phase until ejecting the headrest and may also be utilised to assess the movement of the seat after the pilot has separated when the seat has been propelled out of the aircraft. By constructing the model, the information was used regarding the K-36DM ejection seat, which was supplemented with data on other ejection seats. The demonstrated mathematical model provides a basis to produce a simulation model useful in estimating the efficiency of ejection applying the K-36DM seat.

Keywords

  • K-36DM ejection seat
  • mathematical model of ejection process
Open Access

Methodology of stand tests on the selection of high energy materials for the construction of a tribogenerator

Published Online: 29 Mar 2019
Page range: 543 - 557

Abstract

Abstract

The topic of developing a methodology and a stand test for the evaluation of materials intended for the construction of tribogenerators has been actualized in this article. The proposed method concerns the use of sliding friction in the course of which the mechanical energy is converted into electric energy using the triboelectric and electrostatic effect. The stand test scheme and research methodology are discussed. A preliminary study of friction pairs was carried out, proving the effectiveness of the methodology.

Keywords

  • triboelectricity
  • triboelectric generator
  • triboelectric nanogenerator
Open Access

Training of technical personnel of tactical data LINK

Published Online: 29 Mar 2019
Page range: 559 - 573

Abstract

Abstract

An important area in the process of using and servicing tactical data transmission systems LINK-16 is a system of training operators and technicians. The article presents the results of research related to the modelling and implementation of a modular training program for technical personnel. There were determined ranges of qualification requirements for technical personnel TDL, for the first and second level of service and the possibility of flexible selection of expansion modules for the development of specific skills depending on the destination job.

Keywords

  • TDL
  • training system
  • professional qualifications
  • module
  • modular unit
27 Articles
Open Access

Analysis of aerodynamics and main rotor loads under stalled conditions of helicopter’s main rotor during the pull-up manoeuvre

Published Online: 29 Mar 2019
Page range: 7 - 29

Abstract

Abstract

The article discusses the main features of the applied simulation model of helicopter flight indicating references, where it was elaborated in detail. It focuses on presenting the simulation results of pull-up manoeuvre during which the helicopter does not respond correctly. The reasons for the behaviour as mentioned above were explained based on the results of calculations. The capabilities of the simulation model were used to determine the current loads of particular blades of the helicopter’s main rotor. The results were illustrated by maps of the angles of attack and aerodynamic lift on the surface of the main rotor and the distributions of these parameters along blades on characteristic azimuth for individual manoeuvre phases.

Keywords

  • pull-up manoeuvre
  • simulation
Open Access

Durability of airfield pavement cement concrete in the presence of de-icing agents

Published Online: 29 Mar 2019
Page range: 31 - 53

Abstract

Abstract

In Poland the climatic conditions in the autumn and winter season are particularly severe for concrete infrastructure. Concrete’s resistance to frost and chemical deicing agents determine the durability of cement concrete pavement. An increase in the premature deterioration of airfield pavements exposed to new generation deicing chemicals may suggest that there is a relation between the damages and the application of the deicers. The paper presents selected results of microstructural analysis of the airfield pavements concrete exposed to the deicers based on acetates and formates. Microscopic evaluation was carried out with the scanning electron microscope (SEM). The local chemical compositions of the phases of interest were performed using the Energy Dispersive X-ray analysis (EDX).

Keywords

  • airfield pavements
  • cement concrete
  • de-icing agents
  • microstructure
Open Access

Alternative fuel in the combustion process of combustion engines

Published Online: 29 Mar 2019
Page range: 55 - 81

Abstract

Abstract

The article analyses the impact of emulsified fuel, containing H2O2 hydrogen peroxide, on the emissions of nitrogen oxides and diesel engine smoke. The process of forming toxic components in exhaust gases of reciprocating engines during the engine operation, and the relationship that specifies the hydrogen peroxide decomposition process were presented. The research was carried out with the use of fuel containing 30%, 20% and 10% of hydrogen peroxide. The concentration courses of the nitric oxide (NO) and nitrogen oxides (NOx), as well as the (CO) carbon monoxide concentration and (S) engine smoke courses were shown separately for the external characteristics of the engine. Finally, the importance of knowledge related to the mechanisms of generation of toxic components in exhaust gases in the reciprocating engines was emphasised.

Keywords

  • combustion engines
  • air pollution
  • environmental protection
Open Access

Fatigue tests, self-healing of polymer-matrix composites in unmanned aerial vehicles

Published Online: 29 Mar 2019
Page range: 83 - 106

Abstract

Abstract

This publication presented the main issues related to fatigue of polymer composite materials. It was featured a fatigue stress test based on composite sample, made of carbon fiber-reinforced polymer, using the four-point bending method. The test was carried out with the initial load and using positive load cycles. The perspectives of diagnostics and self-healing of composite materials, including intelligent materials, were also presented.

Keywords

  • fatigue
  • polymer-matrix composites
  • self-healing
  • intelligent materials
Open Access

Investigations of the susceptibility of unmanned aerial vehicles on intensive microwave radiation

Published Online: 29 Mar 2019
Page range: 107 - 118

Abstract

Abstract

Commercially available drone type unmanned aerial vehicles (UAV), as well as parts and subsystems enabling the assemble of UAVs, are becoming more and more widely available, and their performance is constantly improving. The current possibilities of a drone assembled by a hobbyist predispose are not only to be used as a reconnaissance tool but also as a guided missile. The use of a camera with a video stream transmitter simultaneously with virtual reality goggles and video stream receiver gives the pilot an impression of being on the drone, which makes it possible to control it with extreme precision, even at high speeds. The article presents research aimed at determining the extent and type of damage made on exemplary racer drone caused by intense microwave field radiations.

Keywords

  • unmanned aerial vehicles (UAV)
  • drone
  • HPM
  • EM radiation susceptibility
Open Access

Modelling the flight dynamics of aerial target imitator

Published Online: 29 Mar 2019
Page range: 119 - 147

Abstract

Abstract

This article is concerned with the issue related to studying the dynamic properties of the aerial target imitator. Applying the modelling principles, the structure and technical data of aerial target imitator were described and utilising the PRODAS software a physical model of the aerial imitator was developed based on the conducted simulation studies. Mass, aerodynamic and basic parameters of flight path were determined. Then, experimental studies of basic dynamic characteristics were discussed. The comparison of results obtained from experimental and theoretical studies proves the correctness of the developed model.

Keywords

  • flight dynamics
  • ballistics
  • modelling
  • aerial target imitator
Open Access

Procedures concerning preparations of autonomous underwater systems to operation focused on detection, classification and identification of mine like objects and ammunition

Published Online: 29 Mar 2019
Page range: 149 - 168

Abstract

Abstract

The article presented below is a prelude to the process of conducting sea bottom researches with autonomous underwater systems, focused on detection, classification and identification of objects causing possible threat for shipping and maritime environment. An article include guidelines and suggestions for the operators of autonomous underwater vehicles (AUV), mainly concerning preparations for the operation.

Keywords

  • sonar technologies
  • sea bottom researches
  • autonomous underwater systems
Open Access

Evaluation of the possibilities to use imagery reconnaissance sensors to identify the geological-engineering conditions in lowland river channels

Published Online: 29 Mar 2019
Page range: 169 - 189

Abstract

Abstract

The article concerns the issue of using imagery reconnaissance sensors for the identification of geological-engineering conditions in river channels, in the aspect of evaluating the forcing of a water obstacle. It discusses the issues associated with using air platforms (manned and unmanned) in remote sensing surveying of selected fragments of the Vistula and Bug river channels and the correct interpretation of the obtained results, through their verification using bathymetric tests conducted directly in the river channels.

Keywords

  • remote sensing
  • bathymetric measurements
  • imagery reconnaissance
  • morphodynamics
  • lithology
  • imagery reconnaissance sensors
Open Access

Opportunities and barriers regarding the development of selected methods for obtaining hydrogen from bioethanol

Published Online: 29 Mar 2019
Page range: 191 - 222

Abstract

Abstract

The development of the commercial air carriers market causes an increase in the aviation fuel consumption and the air pollution. There are intensive works in order to invent the possibility of supplying the aviation engines with biofuels. The hydrogen gas is needed for technological processes to obtain the synthetic biocomponents from biomass, which met the quality standards for fuels and aviation fuels. Pure hydrogen gas is scarce in the Earth’s atmosphere and has to be derived from petroleum products. Its acquisition currently requires the processing of petroleum-based matter. The whole world is looking for easy, cheap and safe ways of producing hydrogen from a variety of renewable raw materials, that are an alternative to fossil fuels. The article shows the technological potential of experimental methods for hydrogen production from ethanol produced from biodegradable waste, which is widely considered as a renewable and environmentally friendly resource.

Keywords

  • aviation fuels
  • biofuels
  • producing hydrogen from renewable raw materials
Open Access

Critical physicochemical properties of lubricating oils for aviation applications and their significance in terms of flight safety

Published Online: 29 Mar 2019
Page range: 223 - 251

Abstract

Abstract

The article presents the role of lubricating oils for aviation applications, along with their classification, and discusses the key physicochemical properties. It characterises engine, transmission gear, hydraulic and instrumentation oils and their impact on a device operational reliability. It also points out the requirements for these products in relation to the operating conditions and the chemical composition of a product.

Keywords

  • lubricating oils
  • physicochemical properties
  • safety
Open Access

The impact of microstructural non-conformities on microhardness of EN AW 5754 aluminium alloy welded joints made with the use of the TIG method

Published Online: 29 Mar 2019
Page range: 253 - 262

Abstract

Abstract

The article presents the impact of welding non-conformities on microhardness of EN AW 5754 aluminium alloy welded joints made with the use of the TIG method. The results of microhardness tests of welded samples made with various process parameters. The impact of the welding non-conformities disclosed with the use of a tomographic method on the welded joint microhardness were analysed. The studies showed a strong link between the participation of welding non-conformities, welding process parameters and microhardness of welds.

Keywords

  • aluminium alloy
  • weld
  • microstructure
  • non-conformities
  • microhardness
Open Access

Polish experience from the operation of helicopters under harsh conditions

Published Online: 29 Mar 2019
Page range: 263 - 299

Abstract

Abstract

The result of operating the military helicopters in a dusty environment is a loss of performance and premature failures of gas paths of the engines. The efficient protection of the power plant against dust ingestion is tough, especially in the desert. The article summarises the experience accumulated while operating the military helicopters under harsh conditions in Poland and during foreign missions. There were characterised the types of conducted missions, operated helicopters, protection methods of engines and common failures. It was stated that the performance of TV3-117 engines and their particle separation systems was insufficient in the mountains and on the desert (Iraq and Afghanistan). The deterioration of gas paths resulted in the loss of helicopters’ performance and substantially contributed to the few aircraft incidents. The experience gained during foreign missions is used in training the crews and ground personnel and in the programmes of modernisation and renewal of the helicopter fleet.

Keywords

  • dustiness
  • blades
  • engine deterioration
  • turboshaft PZL-10W
  • helicopter
Open Access

Influence of source data on fatigue estimation of a fighter aircraft

Published Online: 29 Mar 2019
Page range: 301 - 322

Abstract

Abstract

Aircraft structures during operation are exposed to fluctuating loads caused both by aerodynamic and inertial loads. This fluctuation leads to the creation of fatigue cycles, which gradually diminish the residual durability of the structure. During the design process, the flight envelope is defined as well as the design load spectrum, which then defines the durability of the structure (often expressed in means of flight hours). However, during the operation of an individual aircraft the actual load cycles can be significantly lower or higher than the designed; therefore, load monitoring is essential for safe operation of aircraft structures.

The following article shows the results of fatigue analysis based on flight data from different flight data recorders for the Su-22 fighter aircraft.

Keywords

  • aircraft fatigue
  • flight data acquisition
  • load monitoring
Open Access

Prototype of the expert tribological diagnostic system of turbine engine

Published Online: 29 Mar 2019
Page range: 323 - 340

Abstract

Abstract

The article presents issues related to the construction of a prototype of an expert tribological diagnostic system for a turbine engine. The database consists of the results of tests on the chemical composition and concentration of the wear products in the oil sample as well as the physico-chemical parameters of the oil. For all diagnostic parameters, threshold values have been defined to classify the level of wear (normal, elevated, increased and emergency). PC Shell software enabling the combination of a rule representation of knowledge and procedural programming was used to build the expert system. The computer application consists of the main module and sources of knowledge dedicated to the applied research methods. The modular structure allows the development of an expert system by adding new research methods.

Keywords

  • turbine engine
  • tribological diagnostics
  • expert diagnostic system
Open Access

An expert system aided method of the blade vibration sources identification with blade-tip timing (BTT) signal decomposition

Published Online: 29 Mar 2019
Page range: 341 - 358

Abstract

Abstract

An expert system aided method of the blade-tip signal decomposition to the turbine blade vibration sources identification is presented. The method utilises a multi-valued diagnostic model based on the discrete wavelet transform. Proposed algorithm consists of four stages: signal decomposition into low- and high-frequency components (approximations and details), approximations and details parameterization, multi-valued encoding of parameters obtained at the second stage, an expert system use of the turbine blade vibration sources identification.

Keywords

  • blade-tip timing
  • multi-valued diagnostic-decision model
  • wavelet transform
  • signal parameterization
  • multi-valued encoding
Open Access

Electrical supply of aircraft during parking

Published Online: 29 Mar 2019
Page range: 359 - 370

Abstract

Abstract

The elaboration discusses selected aspects of parking supply of aircraft with electricity generated by mobile, airfield sources. In terms of sublime electrical and electronic systems, as well as avionic systems installed on-board of contemporary aircraft, the quality of electricity supplied by ground sources results in their manufacturers facing with high requirements that are contained in relevant standards and regulations. The quality of electricity generated by ground sources and their compatibility have a direct impact, among others, on the calibration of aircraft avionics systems during the ground flight preparation, which directly contributes to the safety of air operations. Therefore, the possibility of constant real-time monitoring of the supplied electricity (specific parameters) enabling immediate identification, recording, adjusting the deviations, hence, preventing damage or improper preparation of an aircraft for flight, becomes a non-trivial issue.

Keywords

  • power supply of aircraft on the ground
  • mobile power devices
  • GPU
Open Access

Hydraulic plunger pump contamination sensitivity evaluation

Published Online: 29 Mar 2019
Page range: 371 - 383

Abstract

Abstract

The correct operation of the hydraulic pump and achieving the assumed durability depends on the purity of the used working fluid. The research paper discusses a method for evaluating the contamination sensitivity of a hydraulic plunger pump. The theoretical grounds for evaluating the contamination sensitivity of hydraulic plunger pumps of a hydraulic drive based on the contamination sensitivity factor were presented. An example of evaluating contamination sensitivity of an NP-34M hydraulic plunger pump was discussed.

Keywords

  • hydraulic drive
  • hydraulic pump
  • working fluid
  • impurities in the liquid
Open Access

Pneumatic propellant system model of an emergency parachute system for a vertical take-off and landing UAV

Published Online: 29 Mar 2019
Page range: 385 - 398

Abstract

Abstract

The subject of this publication is a mathematical model of a pneumatic supply system for an emergency parachute system. This system is intended for a vertical take-off and landing UAV. An overview of emergency parachute landing system designs is presented in the introduction. Based on a schematic diagram and a 3D computer model, the construction and operation principles of an emergency parachute system, currently being developed at AFIT, was presented. A mathematical model, which enables the determination of the energy of gas (compressed CO2) stored in the accumulator tank was described. The conducted tests, which involved weighing the accumulator after filling with liquefied CO2 from a special cartridge and equivalent mass ejections were discussed. These tests involved recording the track of the equivalent mass movement and time necessary to determine velocity. The results of calculations regarding the equivalent mass energy imitating an emergency parachute, CO2 volume and mass in the accumulator in liquefied and gaseous state were presented. Based on the conducted calculations and the obtained characteristics, the developed mathematical model was assessed, and the final conclusions formulated.

Keywords

  • emergency parachute
  • pneumatic accumulator
  • pneumatic energy
Open Access

Towards implementation of a formation flying for efficient UAV operations

Published Online: 29 Mar 2019
Page range: 399 - 417

Abstract

Abstract

A flight of a UAV formation is an efficient way to implement surveillance and reconnaissance operations. The usage of a few UAVs as a formation instead of a single vehicle allows creating a distributed network of sensors, which decreases the duration of flight missions and enlarges a total field of view. From a practical point of view, implementations of formation flights require taking into account several separate aspects of flight of UAV such as a quick take-off of several aircraft, aggregating all UAVs in the same space to create swarm and collective flight of the formation towards the area of a surveillance mission. The paper presents the results of researches and experiments carried out towards practical solutions to those aspects. A magnetic launcher is an excellent appliance to put UAV in the air, and its operation could be repeated quickly. Hence, it is ideal to be used in a formation flight. The leader-follower approach based on two-stage switching control is an effective method to aggregate UAVs in the same space while they are flying over large areas. Whereas, the decentralized control of aerial flocking can be used to achieve a coherent flight of UAV formation, which is able to self-organize. Results from simulations and experiments show the effectiveness of each presented aspect and prove their usability in the implementation of formation flights.

Keywords

  • Unmanned Aerial Vehicles (UAVs)
  • UAVs formation control and flight dynamics
  • UAVs swarm
  • aerial flocking
  • leader-follower control
  • UAVs launching systems
  • magnetic levitation launching systems
Open Access

NATO reqiurements as referred to risk in executed contracts

Published Online: 29 Mar 2019
Page range: 419 - 429

Abstract

Abstract

Requirements on risk management are a problem that is described in all of NATO documents written for contract execution purposes. Namely, these documents have become the basis to introduce these requirements into other documents that apply to various aspects of life.

This article describes problems concerning a risk-based approach in executing contracts for the military.

The core of the documents, developed by the NATO members, has been, since the foundation of these documents, the ISO 9001 standard. Although in the history of the NATO document’s period of validity, they had structure identical to the one of ISO 9000 standard series, in their last iteration they gained their specific structure of contents, oriented for specification of the requirements for contracts execution.

Keywords

  • Risk management
  • contract
  • NATO requirements
Open Access

The structure of recurrent circuits of military aircraft – selected problems based on Su-22

Published Online: 29 Mar 2019
Page range: 431 - 445

Abstract

Abstract

This article comprehensively addresses the problems associated with the structure of recurrent circuits of military aircraft with metal fuselage structure. The authors describe the issues concerning the usage of the fuselage as a recurrent circuit of electric current and with negative conductors connecting the fuselage with negative terminals of the receiver or the source. The military aircraft are frequently operated under harsh conditions of increased humidity, dustiness and variable temperatures. All these factors as mentioned above contribute to the occurrence of intensive electrochemical corrosion at the contact points of airframe’s elements or electrical conductors’ with the fuselage. Such contact surfaces should be subject to monitoring – AFIT has developed the numerous procedures for each aircraft.

Keywords

  • recurrent circuit
  • metallization
  • riveted joint
  • negative conductor
  • neutral conductor
  • stray currents
Open Access

Tribological properties of 3D printed components

Published Online: 29 Mar 2019
Page range: 447 - 463

Abstract

Abstract

Additive manufacturing technology is developing in many industries, including aviation, automotive and others. 3D printing offers new possibilities in the field of designing and manufacturing of machines and devices’ components. The paper presents the results of tribological investigations of components produced in FDM printing technology. The authors presented the evaluation of sliding properties of the model friction couple – block on ring type – of available thermoplastic polymers and polymers’ composites under dry friction conditions. The authors assessed the influence of material type and printed structure on resistance to motion of prepared samples.

Keywords

  • additive manufacturing
  • fused deposition modelling
  • tribology
  • friction coefficient
Open Access

Minimisation of empty runs in transport

Published Online: 29 Mar 2019
Page range: 465 - 491

Abstract

Abstract

The issue of minimisation of empty runs in transport, assumptions and calculation method were presented. The example of ineffective usage of transport means was described as well as a procedure algorithm for the optimisation of the above-mentioned issues using the Solver module.

Keywords

  • transport
  • optimisation
  • minimisation of empty runs in transport
  • Solver module
  • Excel
Open Access

The use of a magnetic flux leakage in the assessment of the technical state of a steel wire rope subjected to bending

Published Online: 29 Mar 2019
Page range: 493 - 513

Abstract

Abstract

The technical state of steel wire ropes has a decisive impact on the safety of people using the equipment in which they are installed. The basis for increasing safety is the ability to assess the condition of the working steel wire. The article presents the use of magnetometric sensors to determine the relationship between the number of steel wire rope bends and its magnetic field induction value. This knowledge, referred to ropes working on real objects, allows to determine the state of stress prevailing in them as well as their condition.

Keywords

  • non-destructive testing
  • magnetic flux leakage
  • steel wire rope
  • bending
Open Access

The mathematical model of the pilot’s ejection process by using the K-36DM ejection seat

Published Online: 29 Mar 2019
Page range: 515 - 541

Abstract

Abstract

The article presents a mathematical model of ejection process, which can be used to analyse the movement of the seat-pilot system in flight phase until ejecting the headrest and may also be utilised to assess the movement of the seat after the pilot has separated when the seat has been propelled out of the aircraft. By constructing the model, the information was used regarding the K-36DM ejection seat, which was supplemented with data on other ejection seats. The demonstrated mathematical model provides a basis to produce a simulation model useful in estimating the efficiency of ejection applying the K-36DM seat.

Keywords

  • K-36DM ejection seat
  • mathematical model of ejection process
Open Access

Methodology of stand tests on the selection of high energy materials for the construction of a tribogenerator

Published Online: 29 Mar 2019
Page range: 543 - 557

Abstract

Abstract

The topic of developing a methodology and a stand test for the evaluation of materials intended for the construction of tribogenerators has been actualized in this article. The proposed method concerns the use of sliding friction in the course of which the mechanical energy is converted into electric energy using the triboelectric and electrostatic effect. The stand test scheme and research methodology are discussed. A preliminary study of friction pairs was carried out, proving the effectiveness of the methodology.

Keywords

  • triboelectricity
  • triboelectric generator
  • triboelectric nanogenerator
Open Access

Training of technical personnel of tactical data LINK

Published Online: 29 Mar 2019
Page range: 559 - 573

Abstract

Abstract

An important area in the process of using and servicing tactical data transmission systems LINK-16 is a system of training operators and technicians. The article presents the results of research related to the modelling and implementation of a modular training program for technical personnel. There were determined ranges of qualification requirements for technical personnel TDL, for the first and second level of service and the possibility of flexible selection of expansion modules for the development of specific skills depending on the destination job.

Keywords

  • TDL
  • training system
  • professional qualifications
  • module
  • modular unit

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