The effect of vortex generators on a jet in a cross-flow



Publisher: American Institute of Physics, Publisher: National Aeronautics and Space Administration, Publisher: National Technical Information Service, distributor] in [Woodbury, NY], [Washington, D.C, Springfield, Va

Written in English
Published: Downloads: 526
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Subjects:

  • Flow distribution.,
  • Pressure distribution.,
  • Vortex generators.,
  • Cross flow.,
  • Free flow.,
  • Penetration.,
  • Free jets.,
  • Wind tunnel tests.,
  • Jet flow.

Edition Notes

StatementK.B.M.Q. Zaman and J.K. Foss.
SeriesNASA/TM -- 207881., NASA technical memorandum -- 207881.
ContributionsFoss, J. K., United States. National Aeronautics and Space Administration.
The Physical Object
FormatMicroform
Pagination1 v.
ID Numbers
Open LibraryOL15541866M

  I don't think that you can achieve any significant effect just using vortex generators. At that scale the wing itself is a vortex generator. You might get better results by altering the wing planform, perhaps by moving the wing slightly backward and adding leading edge root extensions to get some of the benefits of a delta wing while keeping. The Effects of Vortex Generator Jet Frequency, Duty Cycle, and Phase on Separation Bubble Dynamics Matthew J. Bloxham Brigham Young University - Provo Follow this and additional works at: Part of theMechanical Engineering Commons This Thesis is brought to you for free and open access by BYU ScholarsArchive.   Re: Vortex Generators My experience, except for the 1st , has been at sea level working a loaded aircraft on and off of ' - ' gravel bars depending on the area while riding high on either Gar Aero's or 29" Bushwheels.   "The effect of skewing on the vorticity produced by an airjet vortex generator" Aeronautical Journal, , vol. , pp. "Optimisation of air-jet vortex generators with respect to system design parameters"Aeronautical Journal, , vol. , pp.

Effect of Vortex Generators on the Performance of Haw t Division of Safety and Fire Engg., SOE, CUSAT blowing. They proposed to use air jets to generate stream wise vortices (AJVG) for interaction control. The effectiveness of air-jet vortex generators in controlling separation was proved. The focus was on the infl uence of AJVGs of. vortex generators are used in turbine blades to reduce the boundary layer separation on the suction side of the low-pressure turbine blades, in transition ducts or inlet channels. Bons et al. [16] used a linear turbine cascade to study the effect of pulsed vortex generator jets on to the flow separation on the suction side of a low-pressure. The paper is concerned with the mathematical modeling of coherent structures of the longitudinal vortex type generated in supersonic turbulent jets by natural oscillations of finite intensity. Secondary regimes induced by Reynolds stresses are investigated by integrating numerically averaged equations of motion of a nonviscous non-heat-conducting compressible gas. Get this from a library! A wind tunnel investigation of the effects of micro-vortex generators and Gurney flaps on the high-lift characteristics of a business jet wing. [Michelle Therese Martuccio; United States. National Aeronautics and Space Administration.].

  J.C. Lin, “Review of research on low-profile vortex generators to control boundary-layer separation”, Progress in Aerospace Sciences, 38, pp. , K. Zaman et al., “The effect of vortex generators on a jet in a cross-flow”, American Institute of Physics, Physics of Fluids, 9 (1), Jan. , pp. K. It is hoped that the results of this research will demonstrate the benefits of applying vortex generators (winglets) on the fins to improve the heat transfer from the air-side of the tube bundle.}, doi = {/}, journal = {}, number =, volume =, place = {United States}, year = {Thu Sep 01 EDT }, month = {Thu Sep 01 Vortex generators delay the separation through higher angles of attack. Car drivers install vortex generators on high-performance automobiles to decrease drag. Additionally, when attached to wind turbine blades, vortex generators can reduce airflow separation, thus .

The effect of vortex generators on a jet in a cross-flow Download PDF EPUB FB2

The effect of vortex generators in the form of tabs on the penetration and spreading of a jet in a cross-flow has been studied experimentally.

It is found that the tab has very little effect when placed on the leeward side, i.e., on the downstream edge of the jet nozzle relative to the free-stream flow.

The effect of vortex generators in the form of tabs on the penetration and spreading of a jet in a cross-flow has been studied experimentally. It is found that the tab has very little effect when.

The effect of vortex generators in the form of tabs on the penetration and spreading of a jet in a cross‐flow has been studied experimentally.

It is found that the tab has very little effect when placed on the leeward side, i.e., on the downstream edge of the jet nozzle relative to the free‐stream flow. A study of the static pressure distribution reveals significantly lower pressures on Cited by: Get this from a library.

The effect of vortex generators on a jet in a cross-flow. [K B M Q Zaman; J K Foss; United States. National Aeronautics and Space Administration.]. The effect of vortex generators in the form of tabs on the penetration and spreading of a jet in a cross-flow has been studied experimentally.

It is found that the tab has very little effect when placed on the leeward side, i.e., on the downstream edge of the jet nozzle relative to the free-stream flow. A study of the static pressure distribution reveals significantly lower pressures on the Cited by:   In the present study, a new method was proposed to promote the jet penetration and enhance the impingement heat transfer.

By placing a delta-winglet vortex generator pair (VGP) in the cross-flow upstream of the jet nozzle, it is found that the impingement heat transfer on the target wall is significantly enhanced. By placing a delta-winglet vortex generator pair (VGP) in the cross-flow upstream of the jet nozzle, it is found that the impingement heat transfer on the target wall is significantly enhanced.

Experiments are carried out to investigate the effects of vortex generators on the jet impingement heat transfer in cross-flow. This study is a continuation of our previous research (Wang et al., ). In the present paper, the jet Reynolds number is fixed at 15, and the cross-flow Reynolds number varies f to 64, The nozzle-to-surface distance to jet diameter ratio is A delta winglet vortex generator (VG), placed in the jet channel and upstream of the jet exit, is used to enhance the heat transfer on the target surface.

The jet Reynolds number is specified at and the range of the cross-flow Reynolds number is from to   An impinging jet heat transfer in cross-flow within and without influence of a vortex generator pair (VGP) is studied using the unsteady Reynolds averaged Navier-Stokes (URANS) and the large-eddy simulation (LES).

The jet Reynolds number is 15, and the cross-flow Reynolds number is 30, The elliptic-blending Reynolds stress model (EBRSM) is implemented and adapted to capture the effect.

Jet impingement cooling is commonly used in gas turbines. Usually the spent air from the upstream jets forms a cross-flow past the downstream jets, which degrades their heat transfer performance.

In the present study, a new method was proposed to promote the jet penetration and enhance the impingement heat transfer. By placing a delta-winglet vortex generator pair (VGP) in the cross-flow.

Vortex generators were originally studied in the late s as a means of controlling (delaying) separation on aircraft wings and in wind tunnels. In these applications the boundary layers were relatively thick and it was found that the most effective kind were the delta-type winglet pairs, at incidence angles of between 10 and 15 degrees to the flow direction, inducing counter-rotating vortices.

The effects of the vortex generator jet(VGJ)attached at the endwall on the corner separation/stall control are investigated by numerical simulation in a high-turning linear compressor cascade. The results show that the corner separation could be reduced significantly, which results in a wider operation range as well as a more uniform exit flow angle and total pressure profile.

Experiments are carried out to investigate the effects of vortex generators on the jet impingement heat transfer in cross-flow. This study is a continuation of our previous research (Wang et al., ). In the present paper, the jet Reynolds number is fixed at 15, and the cross-flow Reynolds number varies f to 64, An experiment is conducted on the effectiveness of a vortex generator (VG) in preventing lift-off of a jet-in-cross-flow (JICF), with film-cooling application in mind.

The jet issues into the boundary layer at an angle of 20 to the free-stream. The effect of a triangular ramp-shaped VG is studied while varying its geometry and location.

We develop a high-resolution three-dimensional vortex simulation of the transverse jet at large Reynolds number and consider jet-to-crossflow velocity ratios r ranging from 5 to A new formulation of vorticity-flux boundary conditions accounts for the interaction of channel wall vorticity with the jet flow immediately around the orifice.

The control effect is sensitive to the change of jet parameters. When 0 deg vortex generation jet could acquire an ideal control effect. As the jet mass increases, the total pressure loss coefficient gradually reduces. A vortex generator (VG) is an aerodynamic device, consisting of a small vane usually attached to a lifting surface (or airfoil, such as an aircraft wing) or a rotor blade of a wind turbine.

VGs may also be attached to some part of an aerodynamic vehicle such as an aircraft fuselage or a car. When the airfoil or the body is in motion relative to the air, the VG creates a vortex, which, by. Interactions of a Dynamic Vortex Generator with a Cross-flow: An Experimental Study The effects of pulse frequency and duty cycle on the skin friction downstream of pulsed jet vortex generators in an adverse pressure gradient turbulent boundary layer.

Effects of Fin and Jet Vortex Generators on the Crossflow. Effects of the vortex generator pair on the jet impingement in cross-flow To augment the impingement heat transfer in cross-flow, a VGP is installed upstream the jet exit on the top wall.

The configuration of the VGP is demonstrated in Fig. 2, and the parameters are listed in Table 1. Vortex generators are nothing fancy. Any little fin sticking in the air at an angle to the wind will work. there are even other non "fin" type objects that work.

(like an "air tab"). Plasma synthetic jet actuators (PSJAs) are particularly suited for high-Reynolds-number, high-speed flow control due to their unique capability of generating supersonic pulsed jets at high frequency (${>}5$ kHz).Different from conventional synthetic jets driven by oscillating piezoelectric diaphragms, the exit-velocity variation of plasma synthetic jets (PSJs) within one period is.

Micro Vortex Generators are small aluminum blades placed in a spanwise line aft of the leading edge of the wing and tail surfaces. They control airflow over the upper surface of the wing by creating vortices that energize the boundary layer.

This results in improved performance and control authority at low airspeeds and high angles of attack. Flow separation at the vehicle’s rear end is the major cause of an aerodynamic drag in a car. In order to delay the flow separation at the rear, bump-shaped vortex generators at the roof end of a car are tested in this paper for two different types of car models Sedan and Hatchback.

The aerodynamic analysis is carried out using GAMBIT and FLUENT for Sedan and Hatchback models. The interaction of a combined vortex generator and a finite-span synthetic jet, i.e., a hybrid actuator, with a zero pressure gradient laminar boundary layer over a flat plate was explored experimentally using Stereoscopic Particle Image Velocimetry (SPIV).

The free stream velocity was U∞ = 10 m/s corresponding to a Reynolds number based on the local boundary layer thickness Reδ ≈   Air-Jet Vortex Generator, request for some papers ROOZBEH: Main CFD Forum: 0: J Vortex Generators Ben Cho: FLUENT: 1: May 5, Modeling the Effect of Vortex Generators on Wings Ben Cho: FLUENT: 0: Ap turbulent scales of forced vortex and free vortex lcw: Main CFD Forum: 3: September 1,   Vortex generator jets (VGJs) have proven to be effective in minimizing the separation losses on low-pressure turbine blades at low Reynolds numbers.

Experimental data collected using phase-locked particle image velocimetry and substantiated with a hot-film anemometer were used to answer fundamental questions about the influence of VGJs on a separated boundary layer. Full text of "Numerical Simulations of Vortex Generator Vanes and Jets on a Flat Plate" See other formats of Vortex Generator Vanes and Jets on a Flat Plate Brian G.

Allan ICASE, Hampton, VA Chung-Sheng Yao and John C. Lin NASA Langley Research Center, Hampton, VA \ 1 st AIAA Flow Control Conference June/St. Vortex generators have been enhancing low-speed stability in a wide variety of aircraft for decades with some impressive results.

Sometimes the differences are substantial, especially in STOL aircraft where low-speed handling is at a premium. “delta” tab, has the greatest effect. Half delta-wing vortex generators are similarly effective in jet mixing enhancement.

A summary of key conclusions from recent studies (Carletti and Rogers,Rogers and Parekh,and Surks et al. ) follows: • Half delta-wing vortex generators allow for more. Based on a scaled 3/4 open jet automotive wind tunnel, this paper studies the effect of vortex generator on the buffeting phenomenon.

The mean velocity, static pressure gradient, turbulent intensity as well as frequencies of fluctuant velocities have been explored experimentally with and without vortex generator.Based on the numerical calculation and analysis of the principle of the lift and thrust of the Fan-wing.

A new scheme for the wing of Fan-wing aircraft-distributed jet blowing wing was presented. Firstly, the mechanism of the formation process of the vortex-induced lift and thrust force of the two kinds of wings was analyzed. Then, the numerical calculation method and validation example were.The maximum total pressure loss reduction is up to % when the incidence is 2°.

The numerical study is further conducted to analyze the flow pattern and the vortex structure. The jet vortex is formed downstream of the jet hole using the vortex generator jets, the cross flow .