Numerical and Experimental Investigations on Windage Heating Effect of Labyrinth Seals

Abstract

The heat load caused by windage heating effect of labyrinth seals seriously influences the sealing of shaft air flow. To reveal the windage heating effect of labyrinth seals to reasonably design an aeroengine rotor, this paper studies the windage heating characteristics of labyrinth seals from theoretical, numerical, and experimental perspectives. First, the theoretical analysis of the windage heating effect of labyrinth is conducted, and the experimental platform of heating labyrinth was established to test the heating labyrinth effect. Then, an RNG k-ε turbulence model was adopted to investigate the characteristics of flow field, leakage characteristics, and windage heating characteristics of labyrinth seals. Last, the influences of pressure ratio, rotational speed and other factors on the windage heating characteristics of labyrinth seals were investigated by theoretical calculation, numerical simulation, and experiment. Through the comprehensive study, we find that: (1) windage heating is indeed induced when leakage flow absorbs the frictional heat caused by the rub of leakage flow with the rotor; (2) when the speed is lower than 1,000 rpm, the windage heating effect is small and enhances with the rise of rotation speed from 1,000−6,000 rpm, and the maximum increase of temperature reaches to 12.87 K; and (3) the pressure ratio increases from 1∶1 to 1∶3, and the temperature rise decreases by ∼7 K. The results of this paper offer a useful insight for the design of labyrinth seals with the emphasis on windage beating effect, to improve the performance of rotor seals.