Mass and Heat Exchange in Rotating Compressor Cavities With Variable Cob Separation

作者：Tom E. W. Nicholas, Mikolaj J. Pernak, Gary D. Lock, James A. Scobie, Hui Tang · 发表于：Journal of Engineering for Gas Turbines and Power · 年份：2024 · DOI：10.1115/1.4066247 · 被引用次数：7 · 研究领域：Advanced Thermodynamic Systems and Engines、Cyclone Separators and Fluid Dynamics、Refrigeration and Air Conditioning Technologies

Abstract Next generation aeroengines will operate at ever-increasing pressure ratios with smaller cores, where the control of blade-tip clearances across the flight cycle is an emerging design challenge. Such clearances are affected by the thermal expansion of the compressor disks that hold the blades, where acute thermal stresses govern operating life. The cavities formed by corotating disks feature a heated shroud at high radius and cooler cobs at low radius. A three-dimensional, unsteady and unstable flow structure is induced by destabilizing buoyancy forces. The radial distribution of disk temperature is driven by a conjugate heat transfer at Grashof numbers of order 1013. Such flows are further influenced by the heat and mass exchange with an axial throughflow of cooling air at low radius, where the interaction depends on the Rossby number and separation of the disk cobs. This paper is the first to study the effect of cob separation ratio on mass and heat exchange for compressor cavities. A model is developed to predict the cavity-throughflow interaction, and disk and fluid-core temperatures. The judicious use of a physics-based methodology provides reliable, reduced-order solutions to the complex conjugate problem, thereby making it appropriate for practical engine thermo-mechanical design. The model is validated by detailed experimental measurements using the Bath Compressor Cavity Rig, where variable disk cob spacings were investigated over a range of engine-represent...