Detonation is a combustion phenomenon that races through at supersonic speeds, significantly impacting combustion chamber performance. Early detonation flow field designs relied heavily on two-dimensional, idealized models. Yet, the aerodynamics research community now widely acknowledges the crucial role of three-dimensional, curved shock waves. In the realm of highspeed aircraft, especially in the development of waveriders and inlets, shock wave research has shifted gears. From oblique to curved shocks, and from two-dimensional to three-dimensional models, this evolution is driven by high-pressurization shock wave research. The principle behind this shift is clear: both the wave structure and detonation flow field evolve from simple, uniform setups to more efficient, non-uniform ones.
Recently, a team of aerodynamic scientists, led by Yancheng You from Xiamen University, has delved into a novel detonation flow field structure. This discovery opens up exciting new avenues for the design of internal detonation channels.
The team published their work in Chinese Journal of Aeronautics on December 10, 2024.
"A revolutionary detonation flow field could offer fresh perspectives on designing internal flow channels", revealed Yancheng You, a professor at Xiamen University's School of Aerospace Engineering and a leading expert in aerodynamic design and propulsion. Leading the study, You and his team introduced a novel basic detonation flow field: the Axisymmetric Inward Turning Curved Detonation Wave (AIT-CDW). They also presented a detailed comparison with two other types of detonation flow fields – the oblique detonation wave and the cone detonation wave. "The AIT-CDW flow field showcases a unique radial compression effect, significantly boosting its compression capabilities and accelerating gas ignition", said You.
"In the design of a detonation chamber, the stable residence of the detonation wave on the induction surface is paramount for ensuring smooth combustion chamber operation," emphasized Yancheng You. To this end, You and his team delved into the combustion behavior of the novel Axisymmetric Inward Turning Curved Detonation Wave (AIT-CDW) basic flow field, focusing on how geometric parameters influence it. Adjustments to the height of the AIT-CDW center body and the shape of the generatrix have a significant impact on flow field stability. By increasing the center body's height and aligning the generatrix shape with the flow direction, the height of the normal detonation caused by reflection can be effectively minimized. This innovation aids in maintaining a stable and efficient combustion process within the flow field, You noted.
Despite these advancements, You cautioned, "There's still a significant amount of research ahead before an engine utilizing the curved detonation basic flow field can be designed and integrated into aircraft."
However, further research is still required to explore this area. The next study will delve into the impact of several key geometric parameters on the Axisymmetric Inward Turning Curved Detonation Wave (AIT-CDW) flow field, including induction surface length, wedge angle, and shape. As the AIT-CDW's induced surface transitions from straight to curved, the design optimization space for the combustion chamber expands significantly, revealing new flow field characteristics due to the curvature change. In the initial design of highspeed vehicles, an integrated design of the internal flow channel is crucial, taking overall performance into consideration. The axisymmetric inward-turning curved-shock basic flow field has already been widely used in the preliminary design of inward-turning inlets, showcasing the benefits of the inward-turning structure in jet mixing. By advancing the design of the initial internal channel, we can push the standing detonation engine closer to practical engineering applications.
Other contributors include Haochen Xiong, Ruofan Qiu, Tao Zhang, Hao Yan from the School of Aerospace Engineering at Xiamen University in Fujian, China.
This work was supported by the National Natural Science Foundation of China (Nos. U20A2069, 62376234 and 123B2037) and the Advanced Aero-Power Innovation Workstation, China (No. HKCX2024-01-017).
About Chinese Journal of Aeronautics
Chinese Journal of Aeronautics (CJA) is an open access, peer-reviewed international journal covering all aspects of aerospace engineering, monthly published by Elsevier. The Journal reports the scientific and technological achievements and frontiers in aeronautic engineering and astronautic engineering, in both theory and practice. CJA is indexed in SCI (IF = 5.3, top 4/52, Q1), EI, IAA, AJ, CSA, Scopus.
