Transpiration cooling of a rotating disk: An experimental study

Heat-transfer coefficients were experimentally determined for a transpiration-cooled rotating disk. A theoretical analysis by previous investigators, based on an assumption of constant properties, was inadequate for predicting results in the present study of air injected into an air environment. However, a simple density ratio was sufficient to realign predicted and experimental results. The range of experiments included injection rates of 0·35–1·04 lb/min ft² and rotation Reynolds numbers of 19 000 – 51 000. The ratio of $\text{h}\text{h}{}_0$ (h₀ = coefficient for impermeable disk) varied from 0·69 to 0·21. Over the range studied, a semi-logarithmic equation correlates the data within 10 per cent.