There are several sources for pressure oscillations in solid propellant rocket motors. Oscillatory flow field is one of them. Free shear layers in motor flow field cause vortex shedding. End edges of propellant grains and baffle edge in two-segmented motors are samples of such zones. These vortices move from their forming points and strike the field walls. The kinetic energy of vortices change ...

In this paper, an unified high-order algorithm for all speeds is developed. The preconditioning matrix of Weiss and Smith combined with a 5th-order WENO scheme for inviscid flux and a fully conservative 4th order central differencing for viscous terms are employed. The unfactored implicit Gauss-Seidel relaxation scheme is used for time marching. The numerical simulation of a natural convective ...

Abstract: This paper reports about progress in the development of numerical tools for adaptive aerodynamic configuration design. We try to illustrate the use of new software components allowing for the parameterized modelling of boundary conditions and the simulation of compressible steady and unsteady viscous flows including a computational flow control model. A coupling of these tools and the...

In this paper, we propose a high order Galerkin discretization scheme for solving steady compressible Navier-Stokes equations. The pointwise numerical fluxes are separated into convective fluxes, acoustic fluxes, and viscous fluxes. The separation of convective flux and viscous flux is to avoid round off errors. The separation of the acoustic flux is due to non-central scheme employed near the ...

Abstract We construct a time-asymptotic expansion with pointwise remainder estimates for solutions to 1D compressible Navier–Stokes equations. The leading-order term is the well-known diffusion wave and higher-order terms are newly introduced family of waves which we call . In particular, these provide an accurate description power-law asymptotics solution around origin $$x=0$$ <mml:math xmlns:...

A variety of shooting methods for computing fully discrete time-periodic solutions of partial differential equations, including Newton-Krylov and optimization-based methods, are discussed and used to determine the periodic, compressible, viscous flow around a 2D flapping airfoil. The Newton-Krylov method uses matrix-free GMRES to solve the linear systems of equations that arise in the nonlinear...