The Influence of Load Distribution on Secondary Flow in Straight Turbine Cascades

This paper describes an experimental study of the three-dimensional flow within two highly loaded turbine cascades subjected to the same overall load but different load distributions. Data were obtained using pneumatic probes, pressure tappings and a surface flow visualization technique. It is found that the general nature of the flow is similar for both cascades. In the exit plane the cascades show different spanwise loss distributions. However, the averaged secondary loss is quite similar in this plane. Examining the measurements further downstream and also by comparing the calculated mixed-out values it becomes clear that a higher magnitude of secondary loss is generated by the front-loaded cascade.