Control of flow separation on a contour bump by jets in a Mach 1.9 free-stream_ An experimental study
نویسندگان
چکیده
Flow separation control over a three-dimensional contour bump using jet in a Mach 1.9 supersonic freestream has been experimentally investigated using a transonic/supersonic wind tunnel. Jet total pressure in the range of 0–4 bar was blowing at the valley of the contour bump. Schlieren photography, surface oil flow visualisation and particle image velocimetry measurements were employed for flow visualisation and diagnostics. Experimental results show that blowing jet at the valley of the contour bump can hinder the formation and distort the spanwise vortices. The blowing jet can also reduce the extent of flow separation appears downstream of the bump crest. It was observed that this approach of flow control is more effective when high jet total pressure is employed. It is believed that a pressure gradient is generated as a result of the interaction between the flow downstream of the bump crest and the jet induced shock leads to the downwards flow motion around the bump valley. & 2016 IAA. Published by Elsevier Ltd. on behalf of IAA. All rights reserved.
منابع مشابه
Flow characteristics of various three-dimensional rounded contour bumps in a Mach 1.3 freestream
Streamwise and spanwise flow pattern over three rounded contour bumps with different flow control strategies employed have been experimentally investigated in a Mach 1.3 freestream. Surface oil flow visualisation, Schlieren photography and particle image velocimetry measurements were used for flow diagnostics. Experimental data showed that in a Mach 1.3 freestream over the baseline plain bump, ...
متن کاملFlow visualisation of a normal shock impinging over a rounded contour bump in a Mach 1.3 free-stream
ABSTRACT An experimental study has been conducted to visualise the instantaneous streamwise and spanwise flow patterns of a normal shock wave impinging over a rounded contour bump in a Mach 1.3 free-stream. A quartz-made transparent shock generator was used, so that instantaneous images could be captured during the oil-flow visualisation experiments. Fluorescent oil with three different colours...
متن کاملModelling of Suddenly Expanded Flow Process in Supersonic Mach Regime using Design of Experiments and Response Surface Methodology
The present work is an attempt to model, analyze, and control the flow at the base of an abruptly expanded circular duct by using design of experiments (DOE) and response surface methodology (RSM). Tiny-jets in the form of orifice were positioned at an interval of 900, 6.5 mm from the primary axis of the main jet of the nozzle. Experiments were conducted to measure two responses namely, base pr...
متن کاملStudy of Parameters Affecting Separation Bubble Size in High Speed Flows using k-ω Turbulence Model
Shock waves generated at different parts of vehicle interact with the boundary layer over the surface at high Mach flows. The adverse pressure gradient across strong shock wave causes the flow to separate and peak loads are generated at separation and reattachment points. The size of separation bubble in the shock boundary layer interaction flows depends on various parameters. Reynolds-averaged...
متن کاملNumerical Simulation of Free Surface in the Case of Plane Turbulent Wall Jets in Shallow Tailwater
Wall-jet flow is an important flow field in hydraulic engineering, and its applications include flow from the bottom outlet of dams and sluice gates. In this paper, the plane turbulent wall jet in shallow tailwater is simulated by solving the Reynolds Averaged Navier-Stokes equations using the standard turbulence closure model. This study aims to explore the ability of a time splitting method ...
متن کامل