Computational Study of the Effects of Protruding Studs Casing Treatment on the Performance of an Axial Transonic Turbofan

摘要

A type of casing treatment consisting of protruding studs near the trailing edge of the fan blades in a turbofan was computationally tested. The results showed that protruding studs have a potential for increasing the stable operating range of the turbofan. An analysis was carried to understand the mechanisms that brought about the change in performance. The analysis suggests that, while the casing treatment imposes a blockage near the casing, it accelerates the flow axially in the rest of the passage and allows for a greater effect on the relative flow angles. These seem to have a positive effect on the operation of the turbofan when flow rates fall below the range of stable operation with the casing having no treatment.