The effect of rotational radius and asymmetric heating on flow and heat transfer in the rotating disc-cone cavity

In the compressor rotor of an aero-engine, a drive cone is typically used to connect the disc and the shaft, forming a disc-cone cavity. In such a cavity, the upstream and downstream discs have different rotational radii; additionally, the inclined cone wall introduces an asymmetric heating effect, making the heat transfer and fluid flow mechanisms more complex. Validated Large Eddy Simulation (LES) was employed for numerical simulation of two disc-cone cavities with different cone angles. For each configuration, simulations were conducted under five different rotational Reynolds numbers over a range of engine representative conditions. The influence of different radii was first investigated. The results demonstrate that the rotational speed corresponding to the peak heat transfer rate in the disc cavity is radius-dependent. Further analysis of disc-cone cavities reveals that at low rotational speeds, heat transfer is dominated by radial heating-driven convection, which is attenuated in large-cone-angle cavities due to their smaller radial temperature gradient component. Conversely, at high rotational speeds, large-cone-angle cavities exhibit enhanced heat transfer. This enhancement is attributed to two mechanisms: the inclined cone surface promotes axial heating-driven convection in the high-radius region, while the smaller rotational radius of the upstream disc intensifies convection in the low-radius region.