为探究叶顶间隙对超临界二氧化碳向心透平机性能的影响，以某超临界二氧化碳向心透平为例，设置不同叶顶间隙，利用计算流体动力学(CFD)仿真软件进行数值模拟。结果表明:当径向间隙等于轴向间隙时，间隙尺寸在0.1~0.5 mm范围内，叶顶间隙与叶轮出口叶高的比值每增大1%，总-静效率降低1.07%左右。当径向间隙不等于轴向间隙时，轴向间隙每增大1%，总-静效率降低0.146%左右，径向间隙每增大1%，总-静效率大约降低0.362%；径向间隙对于透平性能的影响远大于轴向间隙，叶顶间隙在0.1~0.5 mm范围内时，径向间隙对总-静效率的影响约为轴向间隙的2倍。

In order to investigate the influence of blade tip clearance on the performance of supercritical carbon dioxide radial inflow turbine, taking a SCO2 radial inflow turbine as an example, different blade tip clearances were set and computational fluid dynamics(CFD) simulation software was used for numerical simulation. The results show that when the radial clearance is equal to the axial clearance, the clearance size is within 0.1 mm to 0.5 mm, and the totalstatic efficiency decreases by about 1.07% with the increase of the ratio of tip clearance and outlet blade height of 1%. When the radial clearance is not equal to the axial clearance, the totalstatic efficiency decreases by about 0.146% with the increase of axial clearance of 1%; the totalstatic efficiency decreases by about 0.362% with the increase of radial clearance of 1%. The influence of radial clearance on turbine performance is much larger than that of axial clearance, and the influence of radial clearance on totalstatic efficiency of turbine is about twice that of axial clearance when the blade tip clearance size is within 0.1 mm to 0.5 mm.

TK14

国家自然科学基金（51976139）