The Experts below are selected from a list of 7137 Experts worldwide ranked by ideXlab platform
Mark A. Cappelli - One of the best experts on this subject based on the ideXlab platform.
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Dielectric barrier discharge induced boundary layer suction
Applied Physics Letters, 2012Co-Authors: Mark A. CappelliAbstract:Boundary layer downdraft suction and through-surface fluid removal is demonstrated with a streamwise oriented dielectric barrier discharges fabricated into a flat plate immersed in a 3.8 m/s Freestream Flow (Re = 72000). The velocity field is obtained by particle image velocimetry. Suction with through-surface fluid removal is found to thin the boundary layer and increases the velocity gradient in the vicinity of the wall by extracting slower fluid from the inner layer region. The effect of this suction on the boundary layer persists away from the center of the exposed electrode without inducing significant disturbances to the Freestream Flow.
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Plasma Control of a Turbulent Boundary Layer in an Unstarting Supersonic Flow
49th AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition, 2011Co-Authors: Mark A. CappelliAbstract:The manipulation of a turbulent boundary layer during unstart is demonstrated at Mach 4.7 Flow conditions using a dielectric barrier discharge (DBD) actuator. Rayleigh scattering from condensed CO2 particles is used to visualize Flow features such as boundary layers and shock waves at low Freestream static pressure (1kPa) and temperature (60K). Boundary layer thinning is observed when the activated low power (6.8W), low frequency (28kHz) single actuator pair is oriented parallel to the Freestream Flow. The control of the unstart process, initiated by mass addition to the supersonic Flow, is demonstrated through actuation of these boundary layers. The actuation is more effective when relatively thick boundary layers are actuated.
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Dielectric barrier discharge control of a turbulent boundary layer in a supersonic Flow
Applied Physics Letters, 2010Co-Authors: Mark A. CappelliAbstract:We demonstrate effective manipulation of a turbulent boundary layer at Mach 4.7 conditions using a surface dielectric barrier discharge (DBD) actuator. The Freestream conditions of low static pressure (1 kPa) and temperature (60 K) are conducive to the visualization of Flow features using Rayleigh scattering from condensed CO2 particles. The boundary layer thinning is observed when spanwise momentum is induced by the low power (6.8 W), low frequency (28 kHz) single actuator pair oriented parallel to the Freestream Flow.
K P J Reddy - One of the best experts on this subject based on the ideXlab platform.
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enhancement in counterFlow drag reduction by supersonic jet in high enthalpy Flows
Physics of Fluids, 2008Co-Authors: Vinayak Kulkarni, K P J ReddyAbstract:CounterFlow drag reduction by supersonic jet for a 60° apex angle blunt cone flying at hypersonic Mach number is investigated for two different Flow enthalpies using conventional and free piston driven hypersonic shock tunnels. Enhancement in drag reduction has been observed with increase in Freestream stagnation enthalpy. It is shown that the percentage of drag reduction goes up by a factor of 2 when the Flow enthalpy increases by a factor of 2.5 for a given ratio of total pressure of supersonic jet and Freestream Flow.
Liu Jun - One of the best experts on this subject based on the ideXlab platform.
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Studying of solid particle effects on three dimensional jet/Freestream Flow field with particle simulation method
2002Co-Authors: Liu JunAbstract:With particle simulation method employed to trace solid particle's trajectory and ENO scheme adopted to solve NS equation,the Flowfield formed by jet with solid particle vertically injected into supersonic Freestream is numerically studied.The results demonstrated the correctness of above method.It also reflects the influence of solid particle on Flowfield structure and aerodynamic forces and heat flux acted upon the body.
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studying of solid particle effects on three dimensional jet Freestream Flow field with particle simulation method
Journal of Astronautics, 2002Co-Authors: Liu JunAbstract:With particle simulation method employed to trace solid particle's trajectory and ENO scheme adopted to solve NS equation,the Flowfield formed by jet with solid particle vertically injected into supersonic Freestream is numerically studied.The results demonstrated the correctness of above method.It also reflects the influence of solid particle on Flowfield structure and aerodynamic forces and heat flux acted upon the body.
Abdollah Asadollahi-ghohieh - One of the best experts on this subject based on the ideXlab platform.
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Numerical investigation of Freestream Flow effects on thrust vector control performance
Ain Shams Engineering Journal, 2018Co-Authors: Farzad Forghany, Mohammad Taeibe-rahni, Abdollah Asadollahi-ghohiehAbstract:Abstract The current research attempted to apply a numerical investigation for external Freestream-Flow influence on thrust-vector control. The Freestream-Flow Mach numbers varying from 0.05 to 1.1 were studied at different Flow conditions. Computational modeling and simulation of a converging diverging nozzle with shock-vector control structure was achieved with utilizing the Unsteady-RANS approach and Spalart-Allmaras turbulence model. The present investigation has shown that, Freestream-Flow is an essential parameter on performance of shock-vector nozzle. Numerical results demonstrate that, increasing Freestream Mach number would reduce the thrust-vectoring effectiveness. Furthermore, optimizing fluidic-injection angle would decrease the negative influence of external Freestream-Flow on thrust-vectoring performance. Besides, increasing secondary-pressure ratio and decreasing nozzle-pressure ratio at different Freestream-Flows would reduce response time of starting fluidic thrust-vector process. In addition, to conduct the improvement of the future aero-engine designs, the present research attempted to create a database of different external-Flows with main parameters that have effects on thrust-vector control.
Vinayak Kulkarni - One of the best experts on this subject based on the ideXlab platform.
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enhancement in counterFlow drag reduction by supersonic jet in high enthalpy Flows
Physics of Fluids, 2008Co-Authors: Vinayak Kulkarni, K P J ReddyAbstract:CounterFlow drag reduction by supersonic jet for a 60° apex angle blunt cone flying at hypersonic Mach number is investigated for two different Flow enthalpies using conventional and free piston driven hypersonic shock tunnels. Enhancement in drag reduction has been observed with increase in Freestream stagnation enthalpy. It is shown that the percentage of drag reduction goes up by a factor of 2 when the Flow enthalpy increases by a factor of 2.5 for a given ratio of total pressure of supersonic jet and Freestream Flow.
