Ramjet for a supersonic and hypersonic aircraft

A ramjet for a supersonic and hypersonic aircraft, including an elongate body which consists of:

• two sidewalls, flat and parallel to each other;
• a fixed upper wall, integral with said sidewalls and exhibiting, in profile, the rigid general shape of a V open at an obtuse angle, in such a way that said upper wall includes a front flank and a rear flank which are inclined with respect to one another and linked by a ridge which is at least approximately orthogonal to said sidewalls;
• and
• a lower wall mounted movably as one between said sidewalls so as to be able to slide longitudinally in translation, said lower wall also featuring, in profile, the rigid general shape of a V open at an obtuse angle, but reversed with respect to that of said upper wall, said lower wall thus including a front flank and a rear flank which are inclined with respect to one another and linked by a ridge at least approximately orthogonal to said sidewalls,
• said walls of said body delimiting between them:
• an inlet for a flow of oxidant;
• a combustion chamber, which is provided with at least one fuel injector and in which the oxidant/fuel mixing and the combustion of said mixture are carried out;
• and
• an exhaust nozzle, channeling the gases leaving said combustion chamber and formed between said rear flank of the upper wall and the rear flank of the lower wall,
• wherein:
• said fuel injector is arranged in the vicinity of the ridge of said upper wall;
• said front flank of the lower wall includes:
• at least one first face, in a general direction at least substantially parallel to the rear flank of said upper wall and arranged facing said rear flank of said upper wall;
• and
• at least one second face, linked securely to said first face along a joint line at least approximately orthogonal to said sidewalls, said second face being inclined with respect to said first face in such a way that, facing said upper wall, the assembly of said first face and of said second face is concave;
• said ridge of the upper wall faces said second face of said lower wall, while said joint line between said first and second faces lies opposite the rear flank of the upper wall, such that said second face is arranged with regard to said fuel injector with a part facing the rear flank of the upper wall and a part facing the front flank of said upper wall;
• said combustion chamber is formed between, on the one hand, said rear flank of said upper wall and, on the other hand, said first face and the corresponding part of said second face of said lower wall;
• said oxidant inlet is formed between the front flank of said upper wall and the corresponding part of said second face of said lower wall;
• and
• the sliding of the lower wall brings said joint line between said first and second faces closer to said fuel injector so as progressively to modify the geometries of said oxidant inlet and of said combustion chamber, said geometries passing progressively from a first state in which, for a Mach number lying between 1.5 and 3, said oxidant inlet constricts said oxidant flow only slightly and said combustion chamber is long and divergent, to a second state in which, for a Mach number lying between 8 and 12, said oxidant inlet strongly constricts said oxidant flow and said combustion chamber is shorter and exhibits a constant cross section.