Application of heat and mass transfer analogy on hot gas ingestion through rim seal

摘要

This paper presents a theoretical and experimental investigation on developing the relation of concentration-based sealing efficiency and temperature-based sealing efficiency on ingress of transfer by applying the mass and heat transfer analogy. A formula connected these two sealing efficiencies is derived from the Chilton-Colburn analogy. Experiments of heat and mass transfer in ingress are conducted separately to obtain the concentration-based sealing efficiency and temperature-based sealing efficiency respectively, and get a suitable value for the variable "n" originated from the formula derivation. In experiment, annulus Reynolds number is set at 3.25 x 10(5), rotating Reynolds number is changed from 6.26 x 10(5) to 8.34 x 10(5) while the dimensionless sealing air flow rate ranges from 1252 to 5512. The experiment result shows temperature-based sealing efficiency has similar but different distribution inside cavity compared with concentration-based sealing efficiency as Lewis Number is greater than 1 in the experiment. By setting n = 0.105, the experiment data and predicted data from derived formula matches well. In the further discussion of the derived formula, it shows that the difference of concentration-based sealing efficiency and temperature-based sealing efficiency enlarges with the increase of air temperature. (C) 2016 Elsevier Ltd. All rights, reserved.