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Direct Numerical Simulation (DNS) of compressible spatially-developing turbulent boundary layers (SDTBL) is performed at a Mach number of 2.5 and low/high Reynolds numbers over isothermal Zero-Pressure Gradient (ZPG) flat plates. Turbulent inflow information is generated via a dynamic rescaling-recycling approach (J. Fluid Mech., 670, pp. 581-605, 2011), which avoids the use of empirical correlations in the computation of inlet turbulent scales. The range of the low Reynolds number case is approximately 400-800, based on the momentum thickness, freestream velocity and wall viscosity. DNS at higher Reynolds numbers (~3,000, about four-fold larger) is also carried out with the purpose of analyzing the effect of Reynolds number on the transport phenomena in the supersonic regime. Additionally, low/high order flow statistics are compared with DNS of an incompressible isothermal ZPG boundary layer at similar low Reynolds numbers and the temperature regarded as a passive scalar. Peaks of turbulence intensities move closer to the wall as the Reynolds number increases in the supersonic flat plate. Furthermore, Reynolds shear stresses depict a much larger "plateau" (constant shear layer) at the highest Reynolds number considered in present study.
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Passive and active scalar transport phenomena in low Mach number flows
Direct Numerical Simulation (DNS) of spatially-developing turbulent boundary layers (SDTBL) is performed over isothermal/adiabatic flat plates for incompressible and compressible-subsonic (M∞ = 0.5 and 0.8) flow regimes. Similar low Reynolds numbers are considered in all cases with the purpose of assessing modest flow compressibility on low/high order flow statistics of Zero Pressure Gradient (ZPG) flows. The considered molecular Prandtl number is 0.72. Additionally, temperature is regarded as a passive scalar in the incompressible SDTBL with the purpose to examine differences in the thermal transport phenomena of subsonic flows, i.e., passive vs. active scalar. It was found that the Van Driest transform and Morkovin scaling are able to collapse incompressible and subsonic quantities very well.
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- PAR ID:
- 10500007
- Publisher / Repository:
- AIP
- Date Published:
- Journal Name:
- Proceedings of the 21st International Conference of Numerical Analysis and Applied Mathematics
- Format(s):
- Medium: X
- Location:
- Crete, Greece
- Sponsoring Org:
- National Science Foundation
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