Firing tests of models of several Ariane 4 launch vehicle configurations

The Ariane 4 family of the European launch vehicle will comprise six configurations according to the number and the design of the strap-on-boosters in addition to the first-stage, four liquid-propellant main engines. All these engines induce thermal, mechanical, and acoustical loads as a result of interactions of the exhaust streams with the launch pad, with the ambient flow, and between one another. For studying these complex phenomena, ONERA has developed several scale models with engines using the same propellant and operating in the same conditions as the actual ones. A first series of tests was conducted with a 1/20 model fixed in position at various heights above a scale model of the new Ariane launch pad. A second series of tests was conducted with a 1/40 model in ONERA's wind tunnel at transonic and supersonic speeds up to Mach 3 and in ONERA's vacuum chamber for flight altitudes simulated up to 60 km.