**4. Airframe-propulsion integration**

The integration method for the cone-derived waverider and scramjet is introduced as the following. The basic Busemann flow field is decided according to the area ratio between inlet and outlet surfaces of the inward-turning inlet, which can be calculated using the stream thrust analysis. As a result, the Busemann inlet can be obtained. The length of the Busemann inlet is too large, and its upper surface of inlet is horizontal which is not appropriate for integration with the waverider. The Busemann inlet is then truncated.

The angle of the truncation cone should not be too large and is chosen between 3 degree and 5 degree in the present studies. Meanwhile, the semiapex angle of the truncation cone should be smaller than that of the waverider. Accordingly, iterations are necessary to find out the appropriate basic Busemann flow field. The basic flow field of the cone-derived waverider is decided with the design parameters, for example, the inflow Mach number and an appropriate compression angle. The shock angle and the semiapex angle can be calculated. As mentioned before, the semiapex angle must be larger than that of the truncated Busemann inlet. **Figure 26** shows the integration of the inlet and the waverider compression surface. An integration example of the cone-derived waverider and the scramjet can be seen in **Figure 27**.

**Figure 28** compares the contour of Mach number of original cone-derived waverider and integrated vehicle. It can be observed that shock waves attach the bottom leading edges of surfaces of both vehicles. **Figure 29** shows simulation

**Figure 26.** *Integration of cone-derived waverider and truncated Busemann inlet.*

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

#### **Figure 28.**

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

#### **Figure 29.**

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

**47**

**Author details**

**Conflict of interest**

of this work.

Shuai Zhou

provided the original work is properly cited.

*Airframe-Propulsion Integration Design and Optimization*

versus angle of attack of the integration vehicle.

results of the original truncated Busemann inlet and the integrated vehicle. There is a small difference between them since the integration would change the inflow for the inlet. However, the difference is not large. **Figure 30** shows the lift-to-drag ratio

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

The authors declare that there is no conflict of interest regarding the publication

*DOI: http://dx.doi.org/10.5772/intechopen.85187*

**5. Conclusions**

© 2019 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

Yao Zheng\*, Shuai Zhang, Tianlai Gu, Meijun Zhu, Lei Fu, Minghui Chen and

Astronautics, Zhejiang University, Hangzhou, Zhejiang, China

combustor is necessary to perform to verify the design method.

\*Address all correspondence to: yao.zheng@zju.edu.cn

Center for Engineering and Scientific Computation, and School of Aeronautics and

**Figure 30.** *Lift-to-drag ratio versus angle of attack of the integration vehicle.*

results of the original truncated Busemann inlet and the integrated vehicle. There is a small difference between them since the integration would change the inflow for the inlet. However, the difference is not large. **Figure 30** shows the lift-to-drag ratio versus angle of attack of the integration vehicle.
