Development of the HIDEC Inlet Integration Mode

Abstract

An integrated flight propulsion control mode called Inlet Integration has been developed and will be flight demonstrated on an F-15 test aircraft in the Highly Integrated Digital Electronic Control (HIDEC) program. The HIDEC program is conducted by the NASA Ames/Dryden Flight Research Center. The development of the Inlet Integration mode is described in this paper, including the Inlet Integration concept, the control law, its implementation on the test bed aircraft, and the predicted performance benefits. The Inlet Integration system will increase excess thrust (thrustdrag) during supersonic operation. This improvement in aircraft performance is accomplished by utilizing a calculation of engine corrected airflow from the Digital Electronic Engine Control (DEEC) to improve the scheduling of the inlet ramp positions in real time. The improvement in scheduled ramp positions will result in increased inlet performance, hence aircraft performance, while maintaining stable inlet operation. Analyses have shown the Inlet Integration system can increase excess thrust by as much as 13 percent at Mach 2.3, 40,000 ft. This thrust increase will result in increased supersonic acceleration. Inlet integration has the additional feature of improving aircraft supportability by eliminating the need for replacing inlet controllers when higher thrust derivative engines are installed in the F-15.