The flow of a two-dimensional, plane turbulent jet impinging on a porous screen has been studied experimentally. It is shown how the overall flow structure depends on the porosity of the surface. For low screen porosity (β < 0.41, say), transverse wall jets can be formed on both sides of the screen and in extreme cases the axial momentum flux some way downstream of the screen falls to zero, so ...

Acoustic waves trapped in the potential core of subsonic turbulent jets have recently been observed and explained by Towne et al. We show that these waves also radiate outside the jet, primarily into the upstream arc. We provide an experimental identification of the Mach-number dependence of the phenomenon, which indicates that the modes are active even when evanescent, probably due to turbulen...

The current study numerically investigates an active mixing enhancement technique for a supersonic ejector with constant area chamber operating under the critical regime. Streamwise control jet injections are alternatively pulsed at top and bottom sides of entrance. induced oscillation primary enhances bulk between secondary streams. stream penetrates core flow much upstream strategy compared t...

Splattering of droplets during liquid jet impingement on solid targets alters the efficiencies of jet impingement heat transfer processes and chemical containment safety devices, and leads to problems of aerosol formation in jet impingement cleaning processes. A study of the turbulent liquid jet impingement splattering, the evolution of the disturbances on the free surface of a turbulent liquid...

The presence of tones in the acoustic far field isothermal round jets for angles relative to flow direction is investigated Mach numbers between and 2 based on data from both experiments large-eddy simulations. For all numbers, as observed jet near-nozzle region previous studies, peaks are found far-field pressure spectra regardless nozzle-exit boundary-layer properties. They emerge near cutoff...

The present study proposes novel micro-jet impingement heat sink with effusion holes for flow extraction. The design consists of impingement nozzles surrounded by multiple effusion holes to take away the spent fluid. A three-dimensional numerical model is used for steady, incompressible, laminar flow and conjugate heat transfer for the performance analysis of the proposed design. The computatio...

one of the most common methods for controlling and increasing maneuverability of projectiles, especially the ones which move at high altitude and in low density air, is using lateral or reaction jets. the resultant force of the reaction jet is related to the jet and flow parameters. for finding their relation experimental, numerical, and analytical methods have been used. in order to change the...

in this paper, construction of triplet atmospheric plasma jet using argon, air, oxygen and nitrogen gases is reported. bactericidal effect of the plasma jet is also investigated. to that end, longitudinal geometric configuration for the electrodes was chosen because it would increase the jet length. electrical characteristics, jet length dependencies on the applied voltage and gas flow rate wer...