Influence of flow control on aerodynamic properties of an open cavity in rarefied hypersonic flows. (February 2022)

• Record Type: Journal Article
• Authors: Guo, Guangming; Jiang, Sitan; Chen, Hao; Zhu, Lin
• Is Part Of: Acta astronautica. Volume 191(2022)
• Page Start: 404
• Page End: 416
• Publication Date: 2022-02
• Subjects: Cavity -- Flow structure -- Wall heat flux -- DSMC -- Supersonic jet; Astronautics -- Periodicals; Outer space -- Exploration -- Periodicals; Astronautics; Periodicals; 629.405
• DOI: 10.1016/j.actaastro.2021.11.036
• Languages: English
• ISSNs: 0094-5765

Abstract

Abstract: The discontinuity at the thermal protection system tiles covered on an aerospace vehicle is modeled as an open cavity to numerically investigate rarefied hypersonic flows over it under various flow control styles using the direct simulation Monte Carlo method. The influence of flow control on flow structures (e.g., shock wave and vortex) and aerothermal properties (e.g., temperature distribution and wall heat flux) is analyzed in detail. The flow structures and aerothermal properties of the cavity flowfield are both changed greatly by the square control block on the cavity opening line, such as a reduction of about 79.5% of the maximum of wall heat fluxes near the reattachment corner, while these changes are gradually weakened with the control block moving down. The control blocks with different shapes still have the ability to change flow structures and thus the heat flux coefficients over the cavity surfaces, but shape has little effect, and the square control block has the strongest wall heat flux compared with the circular, triangular, and wedged control blocks. For the supersonic jet with different directions, the leftward jet has the best performance in eliminating high temperature gas inside the cavity and over the downstream wall and reducing wall heat fluxes over cavity surfaces, followed by the downward jet. The main reason is that the leftward and downward jets can effectively prevent momentum and energy exchanges between freestream with cavity surfaces. Highlights: DSMC is used to investigate aerodynamic properties of an open cavity in rarefied hypersonic flows. Control block over cavity floor greatly changes cavity flow and aerothermal characteristics. Position of control block rather than its shape has a remarkable impact on aerodynamic properties of cavity flowfield. Leftward jet has the best performance in changing flow structures and reducing wall heat flux, followed by downward jet.