This paper presents an experimental investigation on the primary and secondary peak heat transfer characteristics of obliquely (45°) impinging jet a flat smooth target surface. Local convective coefficients have been calculated through transient liquid crystal thermography technique employing one-dimensional semi-infinite conduction model for The effects Reynolds number (Re) jet-to-target spaci...

The flow and acoustic fields of jets at a Mach number 3.1 impinging on plate the jet nozzle exit, where is diameter, have been investigated using highly resolved large-eddy simulations. perforated with hole diameter , or . full-plate free-jet cases also considered. pressure levels are highest for non-perforated decrease as increases. Compared free jet, they higher by about 5 dB full plate, 4 3 ...

The thermal management of high heat fluxes is a critical roadblock in the way of higher-performance microelectronics. The ongoing reduction in microtransistor size translates into heat fluxes comparable to those encountered in nuclear reactions and rocket nozzles, but under much severer temperature constraints. Although the average heat flux may remain in the vicinity of 100 to 300 W/cm, the pe...

This study investigates the effect of nozzle-plate distance on the acoustic phenomena from a correctly expanded supersonic jet impinging on an inclined flat plate. In the authors’ previous study, the overall sound-pressure-level (OASPL) in the direction almost perpendicular to the plate from the impingement region became highest when the nozzle-plate distance was 15D (D, the nozzle exit diamete...

The characteristics of effectiveness and heat transfer for a row jets impinging on corrugated surface were experimentally investigated. Reynolds number, Re which was calculated based the exit velocity hydraulic diameter nozzle, 20000 jet-to-target spacing, L, varied from 2 to 10 times jet diameter, d. spacing between adjacent jets, Sx, kept constant at 4d. actual angle impingement distance diff...

Experimental and numerical methods were used to explore the cooling performance of a new hybrid device consisting of a slot jet impinging into a micro-channel, thus capitalizing upon the merits of both cooling configurations. The three-dimensional heat transfer characteristics of this device were analyzed using the standard k–e turbulent model. Numerical predictions for liquid PF-5052 show exce...

This paper is presented to study the combustion process and emissions in a direct injection diesel engine. Computations are carried out using a three-dimensional model for flows, sprays, combustion and emissions in Diesel engines. Interactions between combustion and emissions with flow field are considered and it is shown that soot mass fraction increases at regions with low turbulence inten...

Abstract The present study considered an impingement jet using hybrid nanofluid CuO–Cu/water. A single rounded nozzle was used to impinge a turbulent coolant (water) on the hot circular plate at Reynold’s number range of (5,000–15,000). CuO–Cu nanoparticles were physically synthesized 50 nm size and dispersed by one-step preparation method. experimentations conducted with nanoparticle concentra...