Volume 9 (2013): Issue 2 (June 2013)

The gas-liquid two-phase flow is characterized by continuous and local change of surface separation of phases and by their mutual interactions. Due to the instability of the flow, heat transfer and mass, a precise analytical approach is difficult to achieve. Despite these difficulties, efforts are underway to progress from the more frequent empirical studies to reliable analytical models. This requires an accurate research of the processes involved in the two phase flow and how they interact with one another. This paper aims to determine the pressure drop for a two-phase flow in a horizontal pipe of a heating plant. The author compares the results obtained by numerical simulation with existing results in the domain. The mixture is air-water, at an environmental temperature of 25°C.

The present paper thematically fits in the current concern for reducing energy consumption to ensure normal thermal comfort in residential and tertiary building heated spaces. Windows are an important area of the building envelope through which heat dissipates from the interior space to the exterior. As it is known the new insulating window types significantly reduce energy dissipation by both transmission and infiltration. This paper aims to establish the theoretical correlations that exist between different constructive functional parameters of insulating windows, such as gas or gases located between two or three window sheets and low-ε films to be applied on interior faces of the transparent elements. The theoretical work procedures as well as the tabulated and graphical results regarding the thermal resistances for various insulated window structures are presented. The results are analyzed in comparison with the values contained in the C107 regulation for building heat calculations.

In this paper we describe the evaluation of various climatic parameters in establishing their prognostic value in a photochemical smog episode. Our application was validated using real data from the “Cercul Militar National” and “Sos. Mihai Bravu nr. 47-49”, from April 2008 to May 2008. The study was performed on hour averages of pollutant concentrations and meteorological parameters and the statistical analysis was based on multiple regressions. We concluded by using mathematical and statistical methods, [1], that an accurate Global Solar Radiation is one of the most important and essential information in the pollution report.