Research Of Flow And Heat Transfer Characteristics In Rotating Cavities On Compressor

Compressor rotating cavity is a major part of the cooling air flow path of the air through the engine, with a typical pneumatic, heat transfer, and other multi-disciplinary coupling strength characteristics. And it has a great influence on the performance and stable operation of compressor components and aero-engine machine. Then how to predict accurately the flow and heat transfer performance of compressor rotating cavity is the key to achieve high reliability design for aircraft engine. Vortices structures and wall heat transfer performances in the cavity center or near wall region were studied numerically in this paper based on single/multi-cavity models. Then through classification analysis of dimensionless characteristic parameters to study the variation of flow and heat transfer properties in take off、cruise and idle conditions. Finally, refine the influence of different conditions on blade tip clearance by using simplified flow and solid conjugate heat transfer simulation model.This paper mainly contains the following contents:Firstly, the simplified single-chamber and dual-chamber model were used to stimulate flow and heat transfer using Fluid-solid conjugate heat transfer numerical simulation method with the existing checking experimental cases. And on the basis of it, to study the impacts of axial and rotational Reynolds number on cavity flow and heat transfer. Research showed that: flow structure became more complex, vortices increased and became more disorganized, and the heat transfer performance is also significantly enhanced with the upgrading of the rotation Reynolds. However, the flow structure changes in the disk cavity were not obvious with the diversification of the axial flow Reynolds number, but the heat transfer performance was more sensitive to this diversification.Secondly, the multi-disk cavity flow and heat transfer were studied. The simulations of real compressor cavities were carried out with take-off, idling and cruising conditions. Studies showed that: under different conditions, there had a big difference in the flow and heat transfer performance. Specific performance was that with the change in working conditions, there were obvious differences in vortex flow structure, the fluid domain temperature distribution and temperature distribution of the solid wall.Finally, the exploration of thermal deformation and temperature distribution were respectively carried out with the real compressor disk cavity solid domain model under take-off, idling, cruising conditions. Researches showed that: at maximum speed, the thermal deformation was maximal, and the circumferential unevenness was obvious, moreover with reduced speed, this trend was significantly reduced, while the thermal deformation was almost constant in low idle condition.