Demonstration of a Transient Total Pressure Distortion Generator for Simulating Aircraft Inlet Distortion in Turbine Engine Ground Tests

Abstract

The development of high-performance aircraft demands the successful integration of the airframe, engine, and control systems. Advancements in aircraft technologies bring with them the need to improve the computational and experimental tools applied to the airframe-engine compatibility evaluations. This paper focuses on the need to improve one of these tools, the direct-connect turbine engine test method. In the absence of the airframe, the direct-connect test must use devices that simulate the effects of the external airframe and the inlet system on the engine inflow. To meet the challenges presented by advanced aircraft, the Arnold Engineering Development Center (AEDC) embarked on the development of a distortion generator to simulate, in real time, the total-pressure distortion the engine experiences in the flight environment. The AEDC distortion generator development progressed through a five-step process that started with the definition of the distortion characteristics that must be simulated and culminated with the testing of a fully functional transient total pressure distortion generator prototype. Prototype validation tests conducted in an AEDC turbine engine test facility entailed the measurement of steady-state and transient total pressure patterns as well as the high-frequency pressure fluctuations produced. The tests demonstrated the ability to remotely set distortion patterns and the ability to sweep through sequences of patterns at rates commensurate with aircraft maneuvers. The paper focuses on the testing of the prototype. First, the paper provides background information on the motivation for the work and summaries of results from the earlier development steps. Next, the paper provides descriptions of the prototype configuration and the validation tests. It then provides initial test results with examples of remotely set distortion patterns. The paper concludes with a summary of future plans for the prototype as well as for other distortion generators in development.