This thesis presents the results obtained of an experimental study of the flow in a two-dimensional supersonic combustion ramjet (scramjet). Ground based testing of this scramjet was carried out as a part of the University of Queensland led HyShot initiative. The HyShot program aims at atmospheric testing of a scramjet consisting of two two-dimensional combustion chambers in a back to back arrangement. The scramjet will be tested using a vertical trajectory between altitudes of 37km and 22km. A flight Mach No 7.6 ± 0.2 (three sigma variation) is expected. Fins on the booster system will ensure that angle of attack is controlled with ±4°. During the flight the booster system, to which the scramjet is attached, will be given a spin of 5Hz to maintain stability. An attitude correction manoeuvre, that imparts a coning motion on the vehicle, will be conducted during the flight to ensure the scramjet is in the correct attitude prior to the commencement of the flight experiments.
Ground based testing of the scramjet engine has been conducted within the University of Queensland's T4 shock tunnel. The expected flight conditions have determined the ground-based experiments required. The engine has been tested through at +4°, +2°, 0°, -2° and -4° angle of attack. Angle of yaw experiments where conducted at 2° and 4°. The experiments where conducted at a number of different freestream conditions corresponding to flight at 23km, 28km and 35km. Combustion experiments were conducted over an equivalence ratio range of 0.25 to 0.90. The experiments focused on an equivalence ratio range of 0.30 to 0.40, as this was the range where separation was predicted. Tests have determined that a pressure rise of as much as 200% was observed when supersonic combustion was taking place within the engine. Also, evidence has been obtained to show that the inlet design, incorporating features to enable uniform combustor entrance conditions, works as expected through the range of tested angles of attack and yaw. The scram-ram envelope of the engine with respect to altitude and equivalence ratio has also been determined. At the higher tested altitude of 35km, the transition from ramjet to scramjet occurred at an approximate equivalence ratio of 0.40. The transition equivalence ratio decreases to 0.30 at an altitude of 23km. The ground based testing has also produced a large database of information that will be compared to the data obtained during the flight test. This data has also been used to predict the expected data that will be received from the engine during flight.