<abstract xmlns="http://www.w3.org/1999/xhtml">

<p>This paper presents a numerical simulation for predicting the combustor exit temperature pattern of an aircraft engine, developed using the commercial fluid simulation software Ansys Fluent, which assumes a shape probability density function for the instantaneous chemistry in the conserved scalar combustion model and the standard k-ε model for turbulence. We found the compliance of the radial and circumferential non-uniformities of the exit temperature with the experimental data to be insufficient. To achieve much more accurate result, the mixing intensity was enhanced with respect to the initial calculation due to using the reduced value of the turbulent Schmidt number Sc. Numerical simulation was performed for values of the turbulent Schmidt number from Sc = 0.85 (default) up to Sc = 0.2, with results confirming the reduction of radial and circumferential non-uniformities of exit temperature. However, correlation between radial and circumferential non-uniformities is not admissible for these cases. Therefore, we propose to use a temperature-dependent formulation of the turbulent Schmidt number Sc, accounting for the increase in Sc number with increasing gas temperature. A user defined function (UDF) was used to implement the Sc number temperature dependence in Ansys Fluent. The numerical results for the proposed Schmidt number Sc temperature dependence were found to be in acceptable agreement with the experimental data both for radial and circumferential non-uniformities of the exit temperature pattern.</p>
</abstract>

This paper presents a numerical simulation for predicting the combustor exit temperature pattern of an aircraft engine, developed using the commercial fluid simulation software Ansys Fluent, which assumes a shape probability density function for the instantaneous chemistry in the conserved scalar combustion model and the standard k-ε model for turbulence. We found the compliance of the radial and circumferential non-uniformities of the exit temperature with the experimental data to be insufficient. To achieve much more accurate result, the mixing intensity was enhanced with respect to the initial calculation due to using the reduced value of the turbulent Schmidt number Sc. Numerical simulation was performed for values of the turbulent Schmidt number from Sc = 0.85 (default) up to Sc = 0.2, with results confirming the reduction of radial and circumferential non-uniformities of exit temperature. However, correlation between radial and circumferential non-uniformities is not admissible for these cases. Therefore, we propose to use a temperature-dependent formulation of the turbulent Schmidt number Sc, accounting for the increase in Sc number with increasing gas temperature. A user defined function (UDF) was used to implement the Sc number temperature dependence in Ansys Fluent. The numerical results for the proposed Schmidt number Sc temperature dependence were found to be in acceptable agreement with the experimental data both for radial and circumferential non-uniformities of the exit temperature pattern.

Numerical Simulation of the Exit Temperature Pattern of an Aircraft Engine Using a Temperature-Dependent Turbulent Schmidt Number

Transactions on Aerospace Research

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

This paper presents a numerical simulation for predicting the combustor exit temperature pattern of an aircraft engine, developed using the commercial fluid...

Numerical Simulation of the Exit Temperature Pattern of an Aircraft Engine Using a Temperature-Dependent Turbulent Schmidt Number

Published Online: Oct 08, 2021

Page range: 34 - 46

DOI: https://doi.org/10.2478/tar-2021-0015

Keywords
Combustion chamber, exit temperature pattern, turbulent Schmidt number, temperature dependence, numerical simulation, UDF, ANSYS Fluent

© 2021 Igor F. Kravchenko et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Numerical Simulation of the Exit Temperature Pattern of an Aircraft Engine Using a Temperature-Dependent Turbulent Schmidt Number

Published Online: Oct 08, 2021

Page range: 34 - 46

DOI: https://doi.org/10.2478/tar-2021-0015

KeywordsCombustion chamber, exit temperature pattern, turbulent Schmidt number, temperature dependence, numerical simulation, UDF, ANSYS Fluent

© 2021 Igor F. Kravchenko et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Keywords
Combustion chamber, exit temperature pattern, turbulent Schmidt number, temperature dependence, numerical simulation, UDF, ANSYS Fluent