Conjugate Heat Transfer and Turbulent Navier-Stokes Simulations in a Convergent Divergent Nozzle

摘要

In IMI/Rocket System Division, a general CFD code, FLDYNS,rnis developed for steady and unsteady problems. FLDYNS solvesrnTwo-phase, reactive and turbulent flow for external and internalrnflow. Conjugate heat transfer capabilities have been added to therncode for simulating the heat transfer across a solid region or wherernthe solid surface immediately adjacent to the fluid cannot bernadequately represented by thermally insulated, constantrntemperature or heat-flux boundary conditions. The conjugate heatrntransfer functionality in FLDYNS allows the fluid-dynamicrnequations to be solved in the fluid region, with the solution of thernheat equation imposed in a neighboring solid region containingrndifferent values of the heat coefficients. Using appropriate zonalrnboundary conditions at the interface, FLDYNS allows a coupledrnsolution to be computed simultaneously across all zones, with a twowayrntransfer of heat across the boundaries formed between thernzones. This capability of the code has been presented in [1] withrnsome simple examples of steady state cases compared to analyticrnsolutions of the heat equation inside solid region and Blasius flowrnover a heated plate. In this paper we present an implicit solver forrnthe heat equation which enables increasing the pseudo-time step,rnhence, increasing convergence rate. An improved dual timernstepping algorithm based on the RK/implicit smoother isrnintroduced and implemented. Using the improved code, the solutionrnof cooled convergent divergent nozzle is solved. The solution of arncomplex physical problem of heating of a motor nozzle is shown forrnthe steady state case and compared with experimental results [2].rnAlso, the time dependent case of this problem is investigating.