具有轴向温差的封闭转静系盘腔流动和换热特性研究

Study on flow and heat transfer characteristics of a closed rotating static system disk cavity with axial temperature difference

采用数值模拟探究了具有轴向温差下封闭转静系盘腔的流动和换热特性。通过改变热罗斯比数,探究不同工况下盘腔的流动结构、温度分布以及转静盘努塞尔数的径向分布规律。结果表明:具有轴向温差的封闭转静系盘腔与等温封闭转静系盘腔的基本流动结构一致,属于典型的Batchelor流型;与等温封闭转静系盘腔相比,核心区内无量纲周向速度增大,且随着热罗斯比数的增加核心区无量纲周向速度逐渐增加、转静盘边界层内流体的无量纲周向速度也增加;具有轴向温差下,盘腔的温度沿径向逐渐降低,沿轴向先降低、经过核心区温度保持不变、靠近转盘侧继续降低;在热罗斯比数一定时,转静盘的努塞尔数沿径向逐渐增大,随着热罗斯比数的增加,转静盘的努塞尔数有所减小。

The flow and heat transfer characteristics of closed rotor-stator system cavity with axial temperature difference were investigated using numerical simulation.The flow structure,temperature distribution and radial distribution function of Nusselt number of rotor and stator in the disc cavity under different working conditions were investigated by changing the thermal Rossby number.The results showed that the closed rotor-stator system cavity with axial temperature difference was consistent with the basic flow structure of the isothermal closed rotorstator system cavity,belonging to the typical Batchelor flow pattern,and consists of the boundary layer on the rotor-stator surface and the rotating core in the middle;Compared with the isothermal closed rotor-stator system cavity,the rotation ratio in the core area increased,and with the increase of the thermal Rossby number,the rotation ratio in the core area gradually increased,and the dimensionless circumferential velocity of the fluid in the rotor-stator boundary layer increased;With the axial temperature difference,the temperature distribution of the disk cavity changed,and the temperature gradually decreased along the radial direction,and first decreased along the axial direction.The temperature in the core area remained unchanged,and continued to decrease near the side of the rotor;When the thermal Rossby number was constant,the Nusselt number of the rotor and stator gradually increased radially.As the thermal Rossby number increased,the Nusselt number of the rotor and stator decreased.