scholarly journals The Effect of Nozzle-to-plate Spacing on Unconfined Air-assistant Water Impinging Jets

2018 ◽  
Author(s):  
Aspen W. Glaspell ◽  
Kyosung Choo
Keyword(s):  
Impinging Jets ◽  
Plate Spacing

Experimental and Numerical Investigation of Heat Transfer Characteristics of Inline and Staggered Arrays of Impinging Jets

2010 ◽  
Vol 132 (9) ◽  
Author(s):  
Yunfei Xing ◽  
Sebastian Spring ◽  
Bernhard Weigand
Keyword(s):  
Heat Transfer ◽  
Numerical Investigation ◽  
Local Heat Transfer ◽  
Impinging Jets ◽  
Design Tool ◽  
Thermal Design ◽  
Heat Transfer Characteristics ◽  
Transfer Coefficients ◽  
Transfer Characteristics ◽  
Plate Spacing

A combined experimental and numerical investigation of the heat transfer characteristics within an array of impinging jets has been conducted. The experiments were carried out in a perspex model using a transient liquid crystal method. Local jet temperatures were measured at several positions on the impingement plate to account for an exact evaluation of the heat transfer coefficient. The effects of the variation in different impingement patterns, jet-to-plate spacing, crossflow schemes, and jet Reynolds number on the distribution of the local Nusselt number and the related pressure loss were investigated experimentally. In addition to the measurements, a numerical investigation was conducted. The motivation was to evaluate whether computational fluid dynamics (CFD) can be used as an engineering design tool in the optimization of multijet impingement configurations. This required, as a first step, a validation of the numerical results. For the present configuration, this was achieved assessing the degree of accuracy to which the measured heat transfer rates could be computed. The overall agreement was very good and even local heat transfer coefficients were predicted at high accuracy. The numerical investigation showed that state-of-the-art CFD codes can be used as suitable means in the thermal design process of such configurations.

The effect of inclination on impinging jets at small nozzle-to-plate spacing

2012 ◽  
Vol 55 (13-14) ◽  
pp. 3327-3334 ◽  
Author(s):  
Kyosung Choo ◽  
Tae Yeob Kang ◽  
Sung Jin Kim
Keyword(s):  
Impinging Jets ◽  
Plate Spacing

A Study on Resonance Impinging and Wall Jets

2003 ◽  
Author(s):  
Toshihiko Shakouchi ◽  
Takumi Maruyama ◽  
Toshitake Ando ◽  
Koichi Tsujimoto ◽  
Atsushi Watanabe
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Rate ◽  
Transfer Rate ◽  
Impinging Jets ◽  
Heated Plate ◽  
Wall Jets ◽  
Maximum Heat ◽  
Plate Spacing ◽  
Air Jet ◽  
Nozzle Plate

Various kinds of impinging jets are used widely in many industry fields, such as the cooling of a heated plate or electronic components, drying of textiles, film, and paper because of their high heat and mass transfer rates at and near the stagnation point. Many studies on impinging jets from circular and orifice nozzles have been made [1]–[6]. It is well known that as nozzle-plate spacing decreases considerably the heat transfer rate becomes much larger, for example the maximum heat transfer rate of a circular impinging air jet with a low nozzle-plate spacing h/d = 0.1 (d: nozzle exit diameter) and Reynolds number Re = umd/ν = 2.3 × 104 is about 2.17 times of that for h/d = 0.2, but at the same time the flow resistance or operating power of the nozzle-plate system increases considerably. In order to improve or enhance the heat transfer rate, it is needed to increase the impinging mean and fluctuating velocities without increasing the operating power. To achieve this object it is considered to use a resonance jet. In this paper, the flow, acoustic and heat transfer characteristics of resonance free, impinging and wall jets are made clear experimentally. Moreover, flow visualization of the water jet flow by a tracer method is also made to examine the vortex structure at the shear layer and inside the resonance room. As a result, the heat transfer rate of the impinging jet by a resonance nozzle can be improved and enhanced considerably.

Numerical Study of Swirling Impinging Jets With Heat Transfer

2004 ◽  
Author(s):  
Thomas Ha¨llqvist ◽  
Laszlo Fuchs
Keyword(s):  
Heat Transfer ◽  
Swirling Flow ◽  
Numerical Study ◽  
Transition Process ◽  
Impinging Jets ◽  
Transfer Rates ◽  
Statistical Correlations ◽  
Eddy Simulation ◽  
Plate Spacing ◽  
Uniform Grids

This paper deals with numerical simulations of circular impinging jets with heat transfer, by means of Large Eddy Simulation (LES). The LES code uses higher order finite-differences on staggered Cartesian non-uniform grids. The current LES have the potential of dealing with transition as well as providing data on details of larger scale structures, statistical correlations and turbulent spectral content. The impinging circular jet has a nozzle-to-plate spacing ranging from 0.5 to 2 nozzle diameters and the Reynolds number is 20000. Three different swirl numbers have been considered, ranging from non-swirling to strongly swirling flow. From the LES results the transition process in the jet is clearly detected. Swirling flow strongly influences the development of the jet. The wall heat transfer rates become obstructed, even though the turbulence level increases.

CHARACTERISTIC STUDY ON THE LIKE-DOUBLET IMPINGING JETS ATOMIZATION

1999 ◽  
Vol 9 (3) ◽  
pp. 277-289 ◽  
Author(s):  
Wei-Hsiang Lai ◽  
Wennon Huang ◽  
Tsung-Leo Jiang
Keyword(s):  
Impinging Jets

HOLOGRAPHY EXPERIMENTS IN THE BREAKUP REGION OF A LIQUID SHEET FORMED BY TWO IMPINGING JETS

1995 ◽  
Vol 5 (4-5) ◽  
pp. 387-402 ◽  
Author(s):  
B. S. Kang ◽  
Y. B. Shen ◽  
D. Poulikakos
Keyword(s):  
Impinging Jets ◽  
Liquid Sheet

FLOW STRUCTURE AND HEAT TRANSFER IN MULTIPLE IMPINGING JETS

2016 ◽  
Vol 47 (4) ◽  
pp. 359-382 ◽  
Author(s):  
Nabil Kharoua ◽  
Lyes Khezzar ◽  
Zoubir Nemouchi
Keyword(s):  
Heat Transfer ◽  
Flow Structure ◽  
Impinging Jets
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