Analysis Of Fluid Dynamics Of Channel Flow With Porous Wall

Since the channel flows such as transpiration cooling, porous medium with mass injection and bulk gas flow of porous chamber in solid rocket motors (RSM) etc., are characterized by wall mass injection, especially for interior ballastics of RSM, hydrodynamic and combustion instability. The study is focus on typical channel spatial flow with mass injection, which includes the Taylor-Culick flow with arbitrary headwall injection, axisymmetric chamber gas flow with regression walls, two-phase channel flow with particles injection, planar channel flow with tapered wall and mean flow of spinning channel with wall mass injection (especially for RSM). The main conclusions are as follows:(1) Analytical and numerical studies on the Taylor-Culick flow with arbitrary headwall injection are performed and numerical validation of the analytical solutions is in consideration of inviscid, laminar and turbulent flow.(2) Analytical and numerical solutions of axisymmetric chamber gas flow with regression walls are compared. A high order ordinary differtial equation, Reduced N-S equations by spatial similarity andt emporal similarity, is analytically solved with perturbation method. Numerical simulation is based on laminar flow with dynamic mesh techinique to deal with regressing wall. The velocity fields, pressure fields and shear stress distributions are mainly studied for different rates of wall regression a and injection Reynolds number R. The fact that numerical results are well in agreement with the analytical solutions gains confidence in the analytical approximation.(3) Analytical study on the gas-particle two phase mean flow with particles injection is performed with Lagrange method and Euler method respectively. The perturbation approximate solution for small Stokes number with Lagrange method is gained. The self-similarity solution of particle phase flow field is derived and the similarity functions and profiles of velocity and density for different Stokes Number are solved with fourth order R-K method.(4) The channel mean flow with tapered sidewalls is studied with both analytical method and numerical method. The results indicate that the influence of taper angle of sidewalls a and the length of straight sidewalls L is important, the numerical results are well in agreement with the analytical solutions. The pressure drop may be over-estimated only in consideration of straight sidewalls and its influence on other parameters is so on, especially for SRM with the longer chamber and larger tapered combustion surface.(5) The analytic and numerical studies on spinning channel mean flow with porous wall injection is accomplished. The analytical inviscid solutions of spinning mean flow are based on the reduced Euler equations and viscous core corrections to swirl driven mean flow with wall injection is based on tangential momentum equation with the second order viscous terms. Pursuant to conventional asymptotic matching theory, a complete solution is arrived by a separate expansion (the sum of inner and outer expansions), which is cheraterized by The Rankine vortex (sum of free votex and forced vortex) The viscous core radius versus injection velocity with swirl speed is analysed, meanwhile, in consideration of compressibility corrections. Numerical simulation is performed with CFD to study the channel mean flow of a spinning SRM with inner burning cylindrical circle grain. The velocity profiles, viscous core size, segment characteristics of flow in the chamber and secondary vortex near the headwall vernus swirl speed are analysed in details. It provides theoretical basis for the study on the erosion of headwall closure in spinning SRM.