对转盘腔换热特性数值研究

Numerical Study of Heat Transfer Characteristics Inside Counter-Rotating Disk Cavity

关键词:  对转盘腔  换热  努塞尔数  数值模拟  湍流模型

Key words:  Counter-rotating disk cavity  Heat transfer  Nusselt number  Numerical simulation  Turbulence model

摘要:

航空发动机中对转涡轮设计使得对转盘腔内冷气的流动和换热问题被关注。为探究对转盘腔的换热特性及其影响因素，对几何简化后的中心进气对转盘腔模型进行流-热-固耦合数值模拟。结果表明:下游盘换热效果强于上游盘；冷气流量的增大对两盘换热均有显著增强作用，当流量增加一倍时平均努赛尔数升高幅度超过70%；轮盘转速的提高只会增强转速改变轮盘的换热，对另一个转速不变轮盘的换热影响不大；在间隙比G=0.1～0.4，两盘间隙的减小增强上游盘的换热，对下游盘换热影响不大。

Abstract:

With the application of counter-rotating turbine technology in aero-engine， the flow and heat transfer characteristics inside the counter-rotating disk cavity has received concern. To study the heat transfer characteristics inside the counter-rotating disk cavity and its relevant factors， a fluid-thermal-solid coupling simulation of a geometry simplified counter-rotating disk cavity with central inflow was conducted. The results indicated that the heat transfer effect of downstream disk is stronger than that of upstream disk. When the cooling air mass flow increases， the heat transfer effect of two disks is enhanced greatly， the average Nusselt number enhances by more than 70% with the mass flow doubled. When the rotational speed of one disk increases， the heat transfer effect of the disk under rotating variation is enhanced obviously， but the effect is barely observed for the other disk. In the gap radio range of G=0.1～0.4， when the gap of two disks increases， the heat transfer effect of upstream disk is enhanced， but the effect is barely observed for downstream disk.