Three-Dimensional Flow in a Highly Loaded Single-Stage Transonic Fan

Tests have been conducted at DRA Pyestock on a single-stage transonic fan with a very high level of aerodynamic loading at the hub. The objective of the tests was to survey the flow field in detail, with emphasis on studying the three-dimensional viscous aspects of the flow. The test module was highly instrumented. Detailed flow traversing was provided at rotor and stator exit, and replaceable stator cassettes allowed various types of on-blade instrumentation to be fitted. The test rig and instrumentation are described and detailed flow measurements, taken at peak efficiency operation on the design speed characteristic, are presented. These measurements, which are supplemented by flow visualization results, indicate the presence of a severe endwall corner stall in the stator hub flow field. The fan was modeled using the DRA S1-S2 method and these results are also discussed.