Heat Transfer Characterization Methodology for an Oxy-Fuel Direct Power Extraction Combustion System

摘要

The characterization of nozzle heat flux at extreme conditions has been a subject of investigation for a long time.Because of the complexity of the multiple processes involved,including a coupling of turbulent fluid flow,heattransfer,and combustion,designers of similar systems have largely relied on empirical and semi-empiricalcorrelations. However,some of these correlations lead to inaccuracies in the design process. The current studypresents the analysis of a combustor that could be used in a direct power extraction (DPE) configuration. Thecombustor produces flame temperatures of 3300 K and heat fluxes greater than 7 M W /m 2. In this paper,analyticaland two-dimensional numerical heat flux values and temperatures are compared with experimental results. Resultsshow that analytical methods using Bartz correlation with a 40% reduction of the heat transfer coefficient producesimilar results to a much more complicated coupled Navier-Stokes-based model. Both methods match withexperimental results to within 2.8% for coolant heat absorption and 2.5% for the chamber-region channel walltemperature prediction. The analytical model presented in this paper can be employed in other scenarios that useincompressible fluids as coolants,where stratification effects are reduced.