AUTHOR=Lee Shibo , Zhao Yunlong , Luo Jiaqi , Zou Jianfeng , Zhang Jifa , Zheng Yao , Zhang Yang 

TITLE=A Review of Flow Control Strategies for Supersonic/Hypersonic Fluid Dynamics

JOURNAL=Aerospace Research Communications

VOLUME=Volume 2 - 2024

YEAR=2024

URL=https://www.frontierspartnerships.org/journals/aerospace-research-communications/articles/10.3389/arc.2024.13149

DOI=10.3389/arc.2024.13149

ISSN=2813-6209

ABSTRACT=Supersonic and hypersonic flows have gained considerable attention in the aerospace industry in recent years. Flow control is crucial for refining the quality of these high-speed flows and improving the performance and safety of fast aircraft. This paper discusses the distinctive characteristics of supersonic flows compared to low-speed flows, including phenomena such as boundary layer transition, shock waves, and sonic boom. These traits give rise to significant challenges related to drag, noise, and heat. Therefore, a review of several active and passive control strategies is provided, highlighting their significant advancements in flow transitions, reducing drag, minimizing noise, and managing heat. Furthermore, we provide a comprehensive analysis of various research methodologies used in the application of flow control engineering, including wind tunnel testing, flight testing, and computational fluid dynamics (CFD). This work gives an overview of the present state of flow control research and offers insights into potential future advancements.Since Colonel Yeager piloted the X-1 aircraft to break the sound barrier in 1947 [1] , humanity officially entered the supersonic era, as shown in Figure 1. Researchers and engineers have embarked on various scientific explorations and engineering practices in the field of high-speed manned or unmanned aircrafts [2] . The variable Mach number, Ma, is a non-dimensional parameter utilized to quantify compressibility in fluid dynamics, typically employed to differentiate between subsonic (Ma < 1) and supersonic (Ma > 1) flow. In contrast to subsonic flow, the supersonic flow exhibits distinctive physical phenomena, including shock waves, compressibility effects, and boundary layer transition dominated by the second mode, as illustrated in Figure 2. Hsue-Shen Tsien [3] first proposed that when Ma≥5, the flow might be classified as hypersonic flow. Over time, individuals gradually recognized the importance of hypersonic flow, and investigations uncovered several distinct attributes of hypersonic flow in comparison to supersonic flow, such as thin shock layers, entropy layers, viscous interactions, high-temperature flow, low-density flow, real gas effects, and chemical non-equilibrium effects.