The Calculation of Combustor-Wall Temperature Downstream of Total-Head Cooling Rings

摘要

Measurement of heat-transfer coefficient and adiabatic-wall effectiveness are reported downstream of three film-cooling rings each with a different arrangement of total-head holes. These results are compared with predictions based on the finite-difference solution of appropriate three-dimensional conservation equations. The comparison shows that the prediction procedure reproduces the Nussle number trends indicated by the experiments and that the maximum discrepancy between the two is less than 25%„ The procedure was used to predict the influence of velocity ratio, density ratio, lip thickness, initial boundary - large thickness and pitch to diameter ratio on the local Nussle number for ranges of these variables of significance to gas-turbine combustion-chamber practice;the results confirm that only velocity ratio, density ratio and lip thickness have a significant influence.