An Experimental and Theoretical Investigation of Instabilities in Hypersonic Flat Plate Boundary Layer Flow
| Autor: | Ardeshir Hanifi, Volker Wendt, Martin Simen |
|---|---|
| Rok vydání: | 1994 |
| Předmět: |
Hypersonic speed
Ludwieg-Tube Wind Tunnel Local and Nonlocal Instability Theory Computational Mechanics Pitot tube Hypersonic Flow Compressible flow Laminar-Turbulent Transition law.invention Boundary Layer Instabilities symbols.namesake Optics Hot-wire law Hypersonic wind tunnel Nonlocal Wind tunnel Fluid Flow and Transfer Processes Physics Flow Quality business.industry Mechanical Engineering Hot-Wire Anemometry Instability Aerodynamics Mechanics Condensed Matter Physics Flat Plate Boundary layer Mach number Hypersonics Mechanics of Materials symbols business |
| Popis: | As part of an investigation on hypersonic boundary layer transition, the first successful instantaneous hot‐wire and fluctuating pressure measurements have been conducted in the Ludwieg‐tube facility of DLR at a free‐stream Mach number of M∞=5. The disturbance amplitudes [root‐mean‐square (RMS) values] of the fluctuations of Pitot pressure and mass flow are smaller than the values measured in conventional, i.e., continuously driven or blowdown, hypersonic wind tunnels. Hot‐wire measurements in the laminar boundary layer on a flat plate in the same wind tunnel at Mach 5 did not show the expected dominance of high‐frequency second mode instabilities, predicted by linear stability theory and found in other experiments. On the other hand, the growth of natural disturbances within a broad frequency band up to 50 kHz could be observed on the flat plate. The measured amplification rates are in good agreement with theoretical results for three‐dimensional first mode disturbances. The theoretical investigations we... |
| Databáze: | OpenAIRE |
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