One method of heat addition to a supersonic flow is by means of shock-induced combustion or in this particular study a detonation wave. In order to assess the performance potential of a propulsion utilizing such a mode of heat addition a first order inviscid computational scheme based on Godunov's method was developed. This computational method was chosen since it allows the tracking of flow-field discontinuities such as shocks and slipstreams, thus making it possible to generate a vehicle geometry operating at design conditions for given freestream conditions. This same code was also used to determine the flow-field generated by a given body geometry at off-design conditions. Pressures acting on these planar and axisymmetric bodies were calculated and used to determine various performance parameters over a range of Mach numbers. Two configurations consisting of multiple shock external and internal inlet compression, followed by an oblique Chapman-Jouguet detonation wave, were considered. Aerodynamic performance of planar multiple external shock inlet compression vehicles acting as lifting-propulsive bodies (integrated engine-airframe configurations) were also investigated. Off-design performance of these geometries was evaluated by varying the heat addition to the flow in order to obtain the desired thrust-to-dray ratio. For most body geometries operating at flight Mach numbers less than the design Mach number, it was found that no value of heat addition would maintain the design thrust-to-drag ratio. However, for flight Mach numbers greater than the design Mach number it was found that there usually existed at least two values, and in some cases three, of heat addition which would give the design thrust-to-drag ratio.
Performance Characteristics of Hypersonic Detonation Wave Ramjets
1990
13 pages
Report
Keine Angabe
Englisch