Transient buoyancy-induced flow and heat transfer in rotating compressor cavities

作者：Tom E. W. Nicholas, Mikolaj J. Pernak, Jake Williams, Gary D. Lock, James A. Scobie, Hui Tang · 发表于：Applied Thermal Engineering · 年份：2024 · DOI：10.1016/j.applthermaleng.2024.125129 · 被引用次数：6 · 研究领域：Fluid Dynamics and Turbulent Flows、Heat Transfer Mechanisms、Turbomachinery Performance and Optimization

The next generation of aeroengines will feature compressors with increasing pressure ratios and smaller engine cores. Maintaining high efficiencies will require increased sensitivity to reduced blade tip clearances, governed by strong buoyancy-induced flow and heat transfer within the rotating cavities formed by the discs to which the blades are attached. The inherently unsteady flow within these cavities is three-dimensional and unstable. Thermal stresses in the discs are governed by forced and natural convection across large differences in temperature, conjugate heat transfer, centrifugal forces, and disrupted by mass exchange between the core air and an axial cooling throughflow at low radius. The thermo-fluid-dynamics has further complexity during accelerations or decelerations in aeroengine transients. The engine design process requires expedient and reliable aerothermal models to predict the transitory temperatures of the discs, and hence the thermal growth of the rotor and tip clearance. This paper presents, for the first time, a theoretical model to predict compressor cavity transient heat transfer and temperatures from first principles. The reduced-order model was created in close partnership with an experimental programme using an innovative rig designed specifically to explore buoyancy-induced flow in compressor cavities. Unsteady pressure, temperature and heat flux data were collected in the rotating frame of reference under controlled boundary conditions for two ...