Numerical approach for the estimation of throat heat flux in liquid rocket engines

The problem of prediction of heat flux at throat of liquid rocket engines still constitutes a challenge, because of the little experimental information. Such a problem is of obvious importance in general, and becomes even more important when considering reusable engines. Unfortunately, only few indirect experimental data are available for the validation of throat heat flux prediction. On the numerical side, a detailed solution would require a huge resolution and codes able to solve at the same time combustion, boundary layer with possible finite-rate reactions, expansion up to at least sonic speed, and in some cases radiative heat flux. Therefore, it is important to validate, with the few experimental data available in the literature, simplified CFD approaches whose aim is to predict heat flux in the nozzle in affordable times. Results obtained by different numerical models based on a RANS approach show the correctness and quality of the approximations made, indicating the main phenomena to be included in modeling for the correct prediction of throat heat flux.