Film cooling modeling in liquid rocket thrust chambers

The prediction and control of wall heat flux is fundamental in liquid rocket engine design both for sizing and safety purposes. Given the typical operational time scales, active chamber cooling systems are often required to suitably extract heat from the hot-gas flow and keep a reasonably low wall temperature. In order to reduce the number of expensive hot-firing tests and to aid the design process, numerical simulations with different levels of approximations can be employed. In this paper, an overview of the literature covering gaseous film cooling is firstly carried out and discussed, focusing on the 0-D and 1-D reduced-order models available. Then, two different approaches relying on computational fluid dynamics simulations and on a 1-D reduced model are compared for a gaseous hydrogen film-cooled thrust chamber. Results are discussed, compared and validated against experimental data to study their reliability and differences on the predictions along the thrust chamber.