Aerodynamic Performance Analysis of the Hypersonic Airbreathing Vehicle JAPHAR

Abstract

In 1997, DLR and ONERA joined in a common project called JAPHAR (Joint Airbreathing Propulsion for Hypersonic Application Research). The main objective of this project is to develop and test at ground a dual mode ramjet engine (DMR) combining both subsonic and supersonic combustion modes. Another major objective is to define a methodology to establish the thrust-minus-drag balance of the DMR on an experimental vehicle to be flown between Mach number 4 and 8. This paper presents an ongoing effort toward the design of an integrated propulsive system for JAPHAR experimental vehicle. Forebody, inlet and nozzle aerodynamic studies have been conducted in close connection with the system studies and have required CFD analysis as well as wind tunnel experiments. A forebody parametric study based on turbulent Navier-Stokes calculations has been carried out. The main results are given in the paper, demonstrating the advantage of DLR waverider like forebody. In addition, this paper gives an overview of the inlet studies conducted so far at ONERA. An internal compression inlet has been designed and tested in S3MA wind tunnel, between Mach number 3 and 5.5, with and without an incoming boundary layer; Navier-Stokes calculations are in progress to calibrate numerical codes and to provide combustion people with realistic entry flow field conditions. Lastly, a preliminary design of a SERN nozzle (Single Expansion Ramp Nozzle) relying on inviscid calculations is presented.