涡扇发动机涡轮空气系统流动和传热性能的CFD分析

Numerical simulation of flow and heat transfer in turbine cooling system of a turbofan engine

以典型的小型涡轮风扇发动机的涡轮空气系统为研究对象,用数值计算的方法研究了包括高低压涡轮盘腔、导向器内腔、轴承腔和相连的冷却气路在内的流动和传热特性.所研究的是一个多腔相连的多进口、多出口流动与传热问题,在研究中采用了流体域和固体域整体建模耦合计算的方法.根据计算结果,分析了结构参数和气动参数对该系统,尤其是其中轴承腔的温度分布的影响规律,提出了降低轴承腔温度的措施,并分析了各项措施的降温效果.充分展示了数值计算仿真在发动机空气系统分析方面的潜力.

The flow and heat transfer characteristics of a complex turbine cooling system were numerically simulated, which was a multi cavity, multi-inlet and multi outlet system installed in a typical small turbofan engine. The cooling system includes the cavity behind the high pressure turbine disc, the cavity in front of the low pressure turbine disc, supporting guide vane cavity, bearing cavity, and some connecting cooling air passages. In this study, the computational grids in both fluid domain and solid domain were established together, the heat transfer between the two domains was calculated conjointly. Based on the results, the influence of structural parameters and pneumatic parameters on the temperature distribu tion of the system, especially for the bearing cavity, was analysed, and then some measures were taken to lower down the temperature of beating cavity. This study shows the potential power of numerical simulation of fluid flow and heat transfer in complex flow system, helping to improve system design.