Development and Preliminary Validation of A Thermal Analysis Method for Hydrocarbon Regenerative-cooled Supersonic Combustor

Abstract

In this research, a thermal analysis method has been developed to analyze the heat transfer process associated with endothermic hydrocarbon regenerative-cooled structure of a combustor. The complex heat transfer processes relevant to such cooling structure exposed in severe heat environment are modeled by three coupled processes: hot side boundary condition specification, flow and convective heat transfer of fuel within cooling channels and heat transfer in combustor structure with cooling channels embeded. To speed up the simulation process while achieving good accuracy, efforts are made in several aspects: first, hot side heat environment of combustor is obtained either by measurement results from upgraded heat flux sensors developed based on the principle of Gardon heat-flux gauge or by quasi 1-D analysis of combustor using static pressure distribution as input; second, to quantitatively describe flow and heat transfer behavior of hydrocarbon coolant when heavy cracking happens, a five-component surrogate model is developed and together used with a thermal cracking model consisting of 18 species and 24 reactions; third, to account for multiple effects happening in redistribution channels, a special method for flow rate redistribution prediction is developed based on characteristic time scale analysis. The validness of this integrated analysis method is tested by comparing simulation results with measurement data from lab tests of a supersonic model combustor. The overall correctness of exit coolant fuel temperature and wall temperature distribution prediction is within 5% and 10% separately. The fast speed and decent accuracy of this method developed make it very promising to be put into use for hydrocarbon regenerative-cooling analysis. NomenclatureA = area S = perimeter q = heat flux ρ = density h = enthalpy htc = heat transfer coefficient w T = temperature of wall , f T = temperature of fuel w τ = friction of wall f C = friction coefficient t S = Stanton number u N = Nusselt number r P = Prandtl number

Modeling Analysis of an Actively Cooled Scramjet Combustor Under Different Kerosene/Air Ratios

“…The coupled heat transfer processes involving SGL phases shown in Fig. 4 were modeled [28], that is, the flow and combustion in the internal flow path, the heat conduction within the shells, and the heat transfer inside the cooling channels. The channel wall is a two-sided wall that forms the interface between the coolant fluid and the solid combustor shell body, and thus the thermal boundary conditions of the two regions are coupled.…”