Transient 3D conjugate heat transfer simulation of a rectangular GOX-GCH4 rocket combustion chamber and validation

This paper aims to predict the transient temperature fields of rocket combustion chambers. This is important for design and lifetime estimation. A thermally coupled simulation (conjugate heat transfer) model was developed and validated using a combustion chamber experiment with rectangular cross-section and the propellant combination gaseous oxygen-methane. The simulation is based on a thermal finite element model of the structure, Reynolds-averaged Navier-Stokes simulations of nine cooling channel flows and a Reynolds-averaged Navier-Stokes simulation with flamelet extension of the hot-gas flow. A pseudo-transient, implicit Dirichlet-Neumann scheme is used for calculating the equilibrium of structure and fluids. A comparison with experiment shows good agreement with the axial, vertical and transverse temperature distribution in the structure, the transient behavior and the wall heat flux through the cooling channels. It is shown that wall functions in the coolant domains can efficiently decrease the computational effort. (C) 2020 The Authors. Published by Elsevier Masson SAS.