Analysis on the effect of channel aspect ratio on rocket thermal behavior

A trade-off analysis is performed on a test case representative of the cooling system of 1 MN thrust class oxygen/hydrogen liquid rocket engine. The aim of the analysis is to find the channel aspect ratio that maximizes the heat extracted from the hot-gas, for a given coolant pressure drop and hot-gas side wall temperature. The analysis requires many cooling channel flow calculations which are performed by means of a simplified model, referred to as quasi-2D, and an accurate conjugate heat transfer model based on numerical integration of the Navier-Stokes and Fourier's Equations. Both models are able to describe the whole cooling device composed by the coolant and the solid domain, which is exposed the hot-gas, with different computational time and level of details. The fast quasi-2D approach is used to select channel geometries showing the same pressure loss. Discussion is made on results obtained with the more accurate CHT model. Results identify, for the selected test case, an ideal aspect ratio which optimizes cooling performance at large values of channel aspect ratio © 2012 by M. Pizzarelli, F. Nasuti, M. Onofri.