Flow Structures Inside a Rotor-Stator Cavity

[摘要] This paper describes an experimental investigation initiated to determine the threedimensional flow field inside the rim seal cavity of a double-shrouded rotor-statorsystem. Thereby, the effects caused by perturbances in the rotor wall were additionallyexamined. The objective of this work is to provide detailed information about themechanisms that can promote elevated temperature levels in the high pressure section ofa gas turbine. Both ingested hot gas and windage heating generated at the rotor-statorinterface can severely affect the material temperatures and thus considerably increasethe thermal load of the rotating parts.The flow velocities were measured by means of an advanced LDV system capable of providing phase-resolved data. The flow field was determined for two different rotorstator combinations. One of the rotor disks contained small rectangular cavities, located at the disk rim and arranged uniformly in’ the circumferential direction. These elementsare referred to as the shank cavities of the rotor disk.The mechanical torque was measured to demonstrate the influence of these elementson the windage power. The measurements were performed at operating conditions thatare typical for aero-engines. It is shown that a perturbed rotor surface can raise the dragnotably. The experiments were conducted in a high speed test rig at rotational Reynoldsnumbers up toReϕ≈4.2*106. The data were plotted as the dimensionless moment coefficientcMand correlated withReϕand the dimensionless cooling flow ratecw.

[学科分类] 力学，机械学