Serpentine Diffuser Performance with Emphasis on Future Introduction to a Transonic Fan (Postprint)

摘要

A serpentine diffuser for embedded propulsion systems was characterized in terms of pressure recovery and total pressure distortion generation within the discharge flow field. A new experimental facility was constructed and also characterized for this investigation to provide detailed, high fidelity measurements. Diffuser performance was characterized for five different Mach numbers with 195 axial and circumferential static pressure measurements within the diffuser flow path. Pressure distortion at the diffuser discharge was quantified with detailed static and steady total pressure measurements at the 17-inch aerodynamic interface plane (AIP). These measurements were acquired using eight total pressure rakes with ten radial probes each while rotating the diffuser in 5-degree increments, yielding highly detailed pressure distortion measurements at the AIP. The wall static pressure plots of diffuser performance display signs of detached flow along the wall at design conditions. Total pressure contour plots at the AIP show a concentrated pressure distortion pattern at the top center exit of the diffuser resulting in an overall recovery factor of 0.983. Distortion descriptors are presented and discussed.