The optimization of engine-integrated hypersonic waveriders with steady state flight and static margin constraints

The design of an engine-integrated wedge caret-wing waverider is optimized for performance with respect to a set of geometric and flight attitude variables with constraints for steady state flight and static margin. The importance of including the steady state flight constraints is demonstrated. The optimization is done for three performance parameters: Lift to Drag ratio, range coefficient, and a parameter that measures energy height gain per unit weight of fuel. The optimization is also done with different values of static margin constraining the design and the resulting performances compared. The accelerator-type vehicle is optimized at several Mach numbers to find the high Mach number limit for positive thrust. The off-design performance of the cruise vehicle shape is examined for small changes in Mach number from the design point.; Vehicle performance is assessed using analytical relations for the flow over the wings and most of the body. The pre-mixed-shock-induced-combustion scram-jet engine is modeled using a one-dimensional calculation based on Shapiro's influence coefficients. Fuel injection is done prior to the combustor entrance, and flow properties are based on a one-dimensional model using correlations for the shock shape in front of transverse injection. The nozzle flow field is calculated using the method of characteristics.; The imposition of steady state flight constraints on a shape-only optimized vehicle decreases the vehicle performance by up to 53%. Including the steady state flight constraints in the optimization yields an improvement in performance by up to 40% and can give a dramatically different shape. The use of the static margin as a design constraint reduces performance by up to 26% as the static margin decreases from 10% to {dollar}-{dollar}10% and significantly changes the shape of the vehicle.; The introduction of vehicle trim analysis and stability issues is a major advance in the waverider design process. Previous work either did not involve a complete vehicle design, or used a limited set of steady state constraints. The inverse nature of the waverider design process simplifies the inclusion of multidisciplinary analysis in the initial design optimizations because the calculation of the flow field is simplified.