Due to the restricted size of micro-gas turbines, the difficulty of cooling their radial turbines and raising their inlet temperature has been an ongoing focus in their research. In this paper, a back-disk impingement cooling technology for radial turbines is proposed. The study focuses on the influence of the non-uniform circumferential flow field generated by radial turbine volutes on the back-disk’s cooling characteristics. The study was carried out by using a conjugated heat transfer numerical simulation method. The results showed that the circumferential non-uniform distribution of the flow field caused by the volute can significantly impact the relative distribution of cooling efficiency across the surface of the back-disk and can decrease the average cooling efficiency of the back-disk surface by 1.8–6.0% in comparison with when the flow field is uniform. Back-disk jet cooling reduces the efficiency of a turbine and, if the volute is generating a non-uniform flow field, this further decreases the turbine’s efficiency. It was found, however, that the influence of back-disk jet cooling on the expansion ratio of the turbine can be ignored.

由于微型燃气轮机的尺寸有限，冷却其径向涡轮机和提高其入口温度的困难一直是其研究的重点。本文提出了一种用于径向涡轮的后盘冲击冷却技术。该研究集中于径向涡轮蜗壳产生的不均匀圆周流场对后盘冷却特性的影响。该研究是通过使用共轭传热数值模拟方法进行的。结果表明，蜗壳引起的流场周向不均匀分布会显着影响整个后盘表面的冷却效率的相对分布，并使后盘表面的平均冷却效率降低1.8 –6。与流场均匀时相比为0％。背盘式射流冷却会降低涡轮机的效率，如果蜗壳产生的流场不均匀，则会进一步降低涡轮机的效率。但是，发现后盘式射流冷却对涡轮膨胀比的影响可以忽略。