Inlet Distortion

Current practices of engine design for inlet distortion tolerance were developed in the 1960s and 70s, based on empirical correlations.  The resulting design methodologies are experience-based and depend on the individual executing the design. While there is a significant amount of experimental work on assessment of engine stall margins, the mechanisms of distortion transfer and engine responses are largely unknown.  This causes engineers to use overly conservative design criteria, often sacrificing aerodynamic efficiency and operability.  The characterization of the distortion generation, transfer mechanisms and engine response will enable the industry to design for reduced distortion sensitivity and maximize engine-airframe system benefits:

• Improved durability via design incorporation of unsteady interactions
• Improved fuel burn by enabling better management of ingested boundary layers
• New mission requirements for military engines and next generation commercial engines highlight the need for a physics-based, designed-in, capability to characterize inlet distortion sensitivity and transfer mechanisms