超高负荷低压涡轮非定常特性实验

针对某后加载超高负荷低压涡轮叶型的定常与非定常气动特性进行了实验研究.结果表明:由于上游尾迹的作用,在低来流雷诺数与来流湍流度下,尾迹诱导转捩叠加自然转捩可以抑制分离、降低叶型损失.在一个尾迹通过周期,由于尾迹诱导转捩的作用,附面层分离周期性地放大、缩小.同时在吸力面速度峰值点下游观测到了尾迹被割裂为两部分的现象,形成了一个主尾迹与一个副尾迹.副尾迹同样可以诱导转捩,但强度较低,对分离抑制效果有限. 

Experiment of an ultra-high-lift low pressure turbine performance at unsteady state

The performance of an ultra-high-lift after loaded low pressure turbine (LPT) at steady and unsteady state has been investigated experimentally in the present paper. The experiment result show that both of the separation bubble and profile loss have been decreased by the wakes induced transition combined with the separation transition at low inlet Reynolds number and low inlet free stream turbulence intensity under the effect of upstream wakes. In one wake passing periodicity, the boundary layer separation is expanded and shrunken periodically due to the upstream wakes. It has also been seen that the wake is cut into 2 parts-a primary wake and a secondary wake, downstream the blade maximum camber. Even though the secondary wake can induce the transition, the suppression effect of separation is low due to the low wake intensity.