Current trends in the automotive industry towards engine downsizing means turbocharging now plays a vital role in engine performance. The purpose of turbocharging is to increase the engine inlet air density by utilising, the otherwise wasted energy in the exhaust gas. This energy extraction is commonly accomplished through the use of a radial turbine. Although less commonly used, mixed flow turbines can offer aerodynamic advantages due to the manipulation of blade leading (LE) angles, improving performance at low velocity ratios. The current paper investigates the performance of a mixed flow turbine with four volute designs, two radial and two tilted volutes each with one variant with an aspect ratio (AR)=0.5 and one with AR = 2. To ensure constant mass flow parameter (MFP) for aerodynamic similarity, volute area to radius ratio (A/r) was manipulated between the design variants. The maximum variation of cycle averaged normalized efficiency measured between the designs was 2.87%. Purely in the rotor region, the variation in normalized cycle averaged efficiency was 3%. The smallest volute AR designs showed substantial secondary flow development. The introduction of volute tilt further complicated the secondary flow development with the introduction of asymmetry to the flows. It was established that both AR and tilt have a notable effect on secondary flows, rotor inlet conditions and over all mixed flow turbine performance.

汽车行业目前朝着发动机小型化的趋势意味着涡轮增压现在在发动机性能中起着至关重要的作用。涡轮增压的目的是通过利用废气中原本浪费的能量来增加发动机进气密度。通常通过使用径向涡轮来完成这种能量提取。尽管不常用，但由于操纵叶片前角（LE）角，混流式涡轮机可提供空气动力学优势，从而提高了低速比时的性能。本文研究了具有四个蜗壳设计，两个径向蜗壳和两个倾斜蜗壳的混合流涡轮机的性能，每个蜗壳的一个长宽比（AR）= 0.5且一个变量的AR = 2。 ）的空气动力学相似性，蜗壳面积与半径之比（A / r）在设计变体之间进行了操纵。设计之间测得的循环平均归一化效率的最大变化为2.87％。仅在转子区域中，归一化循环平均效率的变化为3％。最小的蜗壳AR设计显示出大量的二次流。蜗壳倾斜的引入由于对流的不对称性而使二次流的发展更加复杂。已经确定，AR和倾斜都对二次流，转子入口条件以及所有混合流涡轮机性能都有显着影响。最小的蜗壳AR设计显示出大量的二次流。蜗壳倾斜的引入由于对流的不对称性而使二次流的发展更加复杂。已经确定，AR和倾斜都对二次流，转子入口条件以及所有混合流涡轮机性能都有显着影响。最小的蜗壳AR设计显示出大量的二次流。蜗壳倾斜的引入由于对流的不对称性而使二次流的发展更加复杂。已经确定，AR和倾斜都对二次流，转子入口条件以及所有混合流涡轮机性能都有显着影响。