DEVELOPMENT STUDY ON ATREX ENGINE

This is the status report of the development study on ATREX engine (Ai r Turbo Ramjet) that is now under way in the Institute of Space and As tronautical Science (ISAS) cooperation with the Ishikawajima Harima He avy Industries (IHI), the Kawasaki Heavy Industries (KHI), the Mitsubi shi Heavy Industries (MHI). ATREX engine will be applied for the propu lsion system of Ay-back booster of TSTO space plane. ATREX is the comb ined cycle (a fan-boosted ramjet) engine providing the effective thrus t from sea level static to flight Mach number 6. ATREX is worked on th e expander cycle with precooling the incoming air as shown in Fig. 1. ATREX employs the tip turbine configuration which allows the compactne ss and the light weight of turbo machinery and the variable geometry a ir-intake and plugnozzle which allow the wide range operation conditio ns. From 1990 to 1992, ''ATREX-500'' has been tested at the sea level static conditions. ATREX-500 is the 1/4-scale model of which fan inlet diameter is 300 mm and overall length 2,200 mm. From 1992 have been p erformed the wind tunnel tests on the primary components of ATREX, the axisymmetric variable geometry airintakes, the precoolers and the var iable geometry plug nozzles. In parallel to the windtunnel tests, the ram combusters have been tested simulating the hypersonic flight condi tions and the application studies on advanced carbon-carbon composite for the tip-turbine and fan assembly has been proceeded. In 1994 initi ated the flight test plan in which ATREX will be verified in the pract ical flight conditions by using an unmanned flying test bench. In 1995 will be tested ATREX-500 installing the precooler under the sea level static conditions to examine the engine performance and the icing on the precooler. The present paper addresses the high loading ram combus ter experiment using the mixer with skewed lobes to generate swirl flo w and the analytical studies and the designs on the precooler and the precooled ATREX engine and the flight test plan. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.