Computation of Transonic Diffuser Flows by a Lagged k - omega Turbulence Model
نویسندگان
چکیده
The lag model proposed by Olsen and Coakley is applied in combination with the baseline k–! two-equation turbulence model to simulate the steady and unsteady transonic ows in a diffuser. A fully implicit time-accurate multigrid algorithm is used to solve the unsteady Navier–Stokes equations and the coupled k–! turbulence model equations. Two test cases are investigated, one with a weak shock in the channel corresponding to an exit-static-toinlet-total pressure ratio Rp=0.82 and the other with a strong shock corresponding to Rp=0.72. Unsteady ows are induced by imposing uctuating backpressure. Computational results are compared with experimental data and demonstrate notable improvement by the lag model for ows with strong shock–boundary-layer interactions.
منابع مشابه
Viscous Computation of Steady/Unsteady Transonic Diffuser Flows
The lag model proposed by Olsen and Coakley (2001) is applied to simulate the steady and unsteady transonic flows in a diffuser. The unsteady flows are induced by imposing fluctuating back-pressures. A fully implicit time–accurate multigrid algorithm is used for solving the Navier-Stokes equations and the coupled k-ω turbulence model equations. Two test cases are investigated, one with a weak s...
متن کاملComputation of Shock Induced Separated Flow with a Lagged k-ω Turbulence Model
The lag model proposed by Olsen and Coakley is incorporated into the baseline two-equation k-ω turbulence model to simulate the transonic and supersonic turbulent separated flow. The performances of the lagged k-ω turbulence model is assessed by computing two transonic airfoil flow cases, the RAE2822 Case 10 and the 18% thick double circular arc airfoil, and a separated nozzle flow. The computa...
متن کاملInternal combustion engines in cylinder flow simulation improvement using nonlinear k-ε turbulence models
The purpose of this paper is to studying nonlinear k-ε turbulence models and its advantages in internal combustion engines, since the standard k-ε model is incapable of representing the anisotropy of turbulence intensities and fails to express the Reynolds stresses adequately in rotating flows. Therefore, this model is not only incapable of expressing the anisotropy of turbulence in an engine c...
متن کاملCritical Drag Investigation for an Axisymmetric Projectile with Choked Base Bleed at High-Subsonic and Transonic Regime Using SST K-? Model
In the following paper, the effects of a choked jet exhausted from the base of a non-lifting body on its total and base drags at sub-sonic and transonic regimes has been numerically investigated. Having surveyed the results of some turbulence models and after comparing with experimental results, an appropriate turbulence model i.e. SST K-?, has been chosen and this model has been used in the su...
متن کامل2DV Nonlinear k-ε Turbulence Modeling of Stratified Flows
The commonly used linear k-ε turbulence model is shown to be incapable of accurate prediction of turbulent flows, where non-isotropy is dominant. Two examples of non-isotropic flows, which have a wide range of applications in marine waters, are saline water flow and the stratified flows due to temperature gradients. These relate to stratification and consequently, variation of density through...
متن کامل