LOCAL HEAT-TRANSFER COEFFICIENTS IN A NOZZLE WITH HIGH-SPEED LAMINAR FLOW

摘要

An experimental investigation of the local heat-transfer coefficient in the throat region of a nozzle operating under conditions of cold wall, thick laminar boundary-layer, low-density, high-speed flow has been conducted. The experimental results have been compared with several analytic procedures for predicting the heat-transfer coefficient in laminar flow. The simple flat plate equation is shown to underestimate the heat-transfer coefficient, while the method of Cohen and Reshotko predicts coefficients which are too large. The incremental flat plate method of Pas qua and Stevens and a modification of a solution of Beck with and Cohen exhibit good results downstream of the nozzle throat when referenced to the value calculated by the simple flat plate equation at the nozzle exit. The effects of thermal radiation upstream of the nozzle throat are indicated.