Design of a Total Pressure Distortion Generator for Aircraft Engine Testing

A new method and mechanism for generating non-uniform, or distorted, aircraft engine inlet flow is being developed in order to account for dynamic changes during the creation and propagation of the distortion. Total pressure distortions occur in gas turbine engines when the incoming flow is disturbed. Dynamic total pressure changes may happen slowly, or may occur very rapidly. The disturbance of the incoming flow can change engine operating characteristics, including lowering the surge limit and creating High Cycle Fatigue incidents. In order to create a distorted flow with dynamic characteristics, a mechanism must be developed that when actuated, can change the distortion pattern and intensity with respect to time.

This work covers the initial design of both the distorting and actuating device. The design chosen is a low force design that is practically independent of flow forces. This allows the system to be easily sized for all flow conditions. The study also includes developing the working design into an overall prototype. Testing is also performed to validate the design as the most advantageous choice.