Feasibility Studies of Advanced Pneumatic Techniques for Control of Turbojet Engines

摘要

Inherent characteristics of pure fluid devices allows consideration of new concepts of closed-loop engine control and offers potential for systems having extreme simplicity, reliability, and environmental ruggedness. To develop these concepts, a two-year analytical and experimental program was conducted to investigate the feasibility of applying advanced pneumatic techniques to the basic control of turbojet engines. System studies were performed to investigate engine parameters most feasible for use in a fluid system control. Analog computer simulations established the fluid system feasibility and determined the fluid component requirements. A simplified fluid control system was conceived and mechanized, to provide closed-loop control of turbine inlet temperature, impending surge, and engine speed. A J85-7 turbojet test engine was provided by the Air Force for installation and testing of the fluid control system. Engine tests at static, sea level conditions demonstrated feasibility of the fluid system. Material studies were conducted to investigate high temperature materials and fabrication techniques necessary for the practical use of fluids. Specific material recommendations were made and practical fabrication methods investigated. Verification of recommended materials and processes were made by actual fabrication and testing under simulated environments. (Author)