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Pressure Fluctuations induced by a Hypersonic Turbulent Boundary Layer
Lian Duan1, Meelan M Choudhari2, Chao Zhang1
1Missouri University of Science and Technology, MO 65409, USA.
Journal of Fluid Mechanics
|January 14, 2021
Summary
Direct numerical simulations reveal how pressure fluctuations change within hypersonic turbulent boundary layers. These findings are crucial for understanding high-speed flow acoustics and aerodynamics.
Area of Science:
- Fluid dynamics
- Aerodynamics
- Acoustics
Background:
- Turbulent boundary layers at hypersonic speeds generate complex pressure fluctuations.
- Understanding these fluctuations is vital for aerospace applications.
Purpose of the Study:
- To analyze pressure fluctuations in a Mach 5.86 turbulent boundary layer using direct numerical simulations.
- To investigate the variations of pressure fluctuations across different wall-normal locations.
Main Methods:
- Direct numerical simulations (DNS) were employed.
- Analysis included statistical and structural variations of pressure fields.
- Comparisons were made with experimental data for validation.
Main Results:
- Pressure fluctuation frequencies decrease away from the wall.
- Propagation speeds differ within the boundary layer and free stream.
- Freestream acoustic fluctuations have lower dominant frequencies and larger spatial scales than surface fluctuations.
Conclusions:
- Pressure fluctuation characteristics vary significantly with wall-normal distance.
- Simulation results align with experimental data, validating the approach for hypersonic flows.
- Increased Mach numbers intensify freestream acoustic fluctuations and alter wave characteristics.
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