Evaluation of K-ℰ Turbulence Model in Numerical Analysis of Store Separation of Delta Wing in Transonic Flow

Document Type : Research Paper

Authors

1 Imam Hossein Jame University, Tehran, Iran

2 Associate Professor/Mechanical & Aerospace faculty, Maalek Ashtar University, Isfahan, Iran

Abstract

One of the most important requirements for the store safe separation from main aircraft is fairly accurate estimate of store behavior after separation. The aim of this study is the evaluation of k-Ɛ turbulence models in numerical investigation of store separation in transition flow (M=1.2). For this purpose we have considered a store standard model and a delta wing as an experimental model. To perform the analysis, firstly, the fluid governing equations have been solved on fixed computational grid by which three components of force and torque components on store have been obtained. Secondly, according to the components and 6 components of store initial position (X, Y, Z, Ɵ, ψ and φ), the new position after a time step was obtained using 6 degree of freedom (DOF) algorithm. Finally using a moving mesh algorithm, the store was located in a new position and the fluid equations on moving grid were solved and the same process has been repeated. The results show, there is no significant difference between viscous and non-viscous analysis results in pitch and yaw modes and both are compliance with experimental data. In roll mode, the non-viscous analysis results there is a significant error (43 percent) and using viscous analysis the error is reduced significantly (24 percent in kƐ RNG). Also the calculation time in viscous analysis is 32 percent more than the non-viscous analysis.

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