Study on Free Heat Dissipation Characteristics of Rear Journal Cavity of High Pressure Compressor

Aero-engine secondary flow air system plays an important role. In the shutdown state, the rotor structure of high temperature compressor carries out free heat dissipation to the atmosphere. Under the action of natural convection, three-dimensional circumferential non-uniform temperature field is formed, which leads to the bending deformation of the structure and brings the risk of grinding of the rotating parts. Aiming at the above problems, this paper takes the multistage journal cavity of aero-engine high-pressure compressor as the research object, and studies the flow and heat transfer characteristics of the structure under the condition of free heat dissipation through experiments and three-dimensional fluid-thermo structure coupling numerical simulation. It is found that in the journal cavity, the high-temperature gas accumulates in the upper half of the region, and the external cold air mainly flows into the lower half of the region. The structural differences between the conventional disk cavity and the journal cavity also have an impact on the flow structure and heat transfer effect inside the journal cavity, and finally lead to the three-dimensional non-uniform temperature distribution characteristics of “upper heat and lower cold, front heat and later cold”.