In this work, the influence of thickness and solidity of guide vane on the unsteady flow of a radial inflow turbine with variable nozzle has been numerically studied. Three vanes with the thickness changes from 0.3 to 0.1 and the solidity changes from 1.43 to 2.86, were chosen for this study. By investigating the unsteady flow field, it is found that the vane with low thickness and high solidity (vane B) can reduce shock by 75 % compared to the vane with high thickness and low solidity (base model); meanwhile, it can also mitigate the nozzle endwall leakage flow thus improves the flow uniformity of rotor inlet. As the intensity of shock and nozzle leakage flow were mitigated, the aerodynamic loading fluctuation of rotor blade can be weakened effectively, which will lead to improved rotor blades forced response. However, at small opening, vane B shows about 0.5 % lower efficiency than the base model; at large open condition, the efficiency degradation of vane B is up to 1.4 %. Therefore, there is a trade-off between the efficiency and forced response when choosing the nozzle vane solidity and thickness.

在这项工作中，数值研究了导向叶片的厚度和坚固性对带有可变喷嘴的径向流入涡轮机非定常流动的影响。本研究选择了三个叶片，其厚度从0.3到0.1变化，而坚固度从1.43到2.86变化。通过研究非恒定流场，发现与高厚度和低强度的叶片（基础模型）相比，低厚度和高强度的叶片（叶片B）可以将冲击降低75％。同时，它还可以减轻喷嘴端壁的泄漏流量，从而提高转子入口的流量均匀性。由于减轻了冲击强度和喷嘴泄漏流，可有效减弱转子叶片的气动载荷波动，从而改善转子叶片的受力响应。但是，在小开口处 叶片B的效率比基本模型低约0.5％；在大开度条件下，叶片B的效率下降高达1.4％。因此，在选择喷嘴叶片的坚固性和厚度时，必须在效率和强制响应之间进行权衡。