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 study, cavitation flow around a hydrofoil and its radiated hydro-acoustic fields were numerically investigated, with an emphasis on the effects of viscous flux vectors. The full three-dimensional unsteady compressible Reynolds-averaged Navier–Stokes equations were numerically solved. The mass transfer model was adopted to model phase changes between liquid water and vapor. To resolve th...

High-order Discontinuous Galerkin (DG) methods have shown a lot of promise in being able to provide high accuracy and efficiency as well as the flexibility to handle complex unstructured grids. However in order to solve compressible flow problems effectively, we need to be able to detect discontinuities/shocks in the flow and capture them effectively such that the solution accuracy is not affec...

This paper reviews the formulation and application of optimization techniques based on control theory for aerodynamic shape design in both inviscid and viscous compressible flow. The theory is applied to a system defined by the partial differential equations of the flow, with the boundary shape acting as the control. The Frechet derivative of the cost function is determined via the solution of ...

These Lecture Notes review the formulation and application of optimization techniques based on control theory for aerodynamic shape design in both inviscid and viscous compressible flow. The theory is applied to a system defined by the partial differential equations of the flow, with the boundary shape acting as the control. The Frechet derivative of the cost function is determined via the solu...

where the symbols ∆, ∇, and ∇· stand for the Laplacian, gradient, and divergence operators, respectively (∆u is the vector of components ∆ui); the number μ is a viscous constant; f is a given vector function; β = (U,V)t is a given C1 function. The system (1.1) may be obtained by linearizing the steady-state barotropic compressible viscous Navier-Stokes equations without an ambient flow (see [8,...