Three-dimensional viscous flow simulations over the VLS using overset grids

Abstract

The present work is inserted into an effort to develop a Chimera flow simulation code capable of handling general launch vehicle configurations. The paper is primarily concerned with presenting results of laminar and turbulent viscous simulations of flows over the first Brazilian satellite launch vehicle, the VLS, during its first-stage flight. The finite difference method is applied to the governing equations written in conservation-law form for general body conforming curvilinear coordinates. The spatial discretization is accomplished with a central difference scheme in which artificial dissipation terms, based on a scalar, non-isotropic model, are added to the numerical scheme to maintain stability. The time march process is accomplished with a 5-stage, 2nd-order accurate, Runge-Kutta scheme. The results here included are indicative of the current status of the Chimera flow simulation capability under development by the authors. The results also highlight interesting features of the flow over the complete VLS and point out the importance of the inclusion of viscous effects for flow simulation over such complex vehicles

Numerical simulation of supersonic jet instability modes of plane and notched rectangular nozzles

“…Hence Baldwin-Lomax turbulence model is selected to simulate macroscopic motions of free supersonic jets from rectangular nozzles because it has been known as a suitable turbulence model for high-speed flows with thin attached boundary-layers. It has also been used for the simulations where the fast solutions while keeping the reasonable accuracy of solutions and where the robustness and reliability of simulations are more important than the detailed flow physics as stated in references [27][28][29][30][31][32][33][34][35]. It is also known and evaluated that it does not have much convergence problems and give completely unphysical results.…”

Passive Control of Supersonic Rectangular Jets through Boundary Layer Swirl

“…Hence Baldwin-Lomax turbulence model is selected to simulate macroscopic motion of rectangular supersonic jets since it has been recognized as a suitable turbulence model for fast simulations while keeping the solutions reasonably accurate and where the robustness and reliability of simulations are more important than the detailed flow physics [1,3,8,23]. After obtaining the macroscopic physical motions of rectangular supersonic jets by Baldwin-Lomax turbulence model, Chien k-ε turbulence model is used to enhance shock waves which are characterized by large pressure gradients.…”