**5. Conclusions**

*Hypersonic Vehicles - Past, Present and Future Developments*

*Comparison on simulated Mach contour of original waverider and integration vehicle. (a) Original waverider.* 

*Comparison on simulated Mach contour of original Busemann inlet and integration vehicle. (a) Original* 

**46**

**Figure 30.**

**Figure 27.** *Integration vehicle.*

**Figure 28.**

**Figure 29.**

*Busemann inlet. (b) Integration vehicle.*

*Lift-to-drag ratio versus angle of attack of the integration vehicle.*

*(b) Integration vehicle.*

Airframe-propulsion integration design method is investigated in the present study. The design methods for the waverider and each components of the scramjet are introduced. The integration method between the waverider and the scramjet is described. The overall optimization for the whole scramjet flowpath is optimized with quick engineering estimation method to provide appropriate performance criteria, which are then used to design three-dimensional component configurations.

Additionally, optimization is performed for the waverider and scramjet components with surrogate modes and CFD simulations. Numerical studies are carried out to find out the performances of the waverider and each component of the scramjet to check whether they can work normally under the design conditions. In the future, the design method for the dual-mode combustor (ramjet and scramjet) will be considered. The numerical simulation for the whole scramjet or dual-mode combustor is necessary to perform to verify the design method.
