HEAT TRANSFER FROM A ROTATING DISK WITH LIQUID JET IMPINGEMENT

1978 ◽  
Author(s):  
H.J. Carper, Jr. ◽  
D.M. Deffenbaugh
Keyword(s):  
Heat Transfer ◽  
Jet Impingement ◽  
Rotating Disk ◽  
Liquid Jet

Numerical Simulation of Transient Thermal Transport on a Rotating Disk Under Partially Confined Laminar Liquid Jet Impingement

2010 ◽  
Vol 132 (5) ◽  
Author(s):  
Jorge C. Lallave ◽  
Muhammad M. Rahman
Keyword(s):  
Heat Transfer ◽  
Steady State ◽  
Finite Thickness ◽  
Jet Impingement ◽  
Rotating Disk ◽  
State Condition ◽  
Bottom Surface ◽  
Liquid Jet ◽  
Steady State Condition ◽  
Solid Disk

Abstract This paper considers the transient conjugate heat transfer characterization of a partially confined liquid jet impinging on a rotating and uniformly heated solid disk of finite thickness and radius. A constant heat flux was imposed at the bottom surface of the solid disk at t=0, and heat transfer was monitored for the entire duration of the transient until the steady state condition was reached. Calculations were done for a number of disk materials using water as the coolant, covering a range of Reynolds numbers (225–900), Ekman numbers (7.08×10−5−∞), nozzle-to-target spacing (β=0.25–1.0), confinement ratios (rp/rd=0.2–0.75), disk thicknesses to nozzle diameter ratios (b/dn=0.25–1.67), and solid to fluid thermal conductivity ratios (36.91–697.56). It was found that a higher Reynolds number decreases the time to achieve the steady state condition and increases the local and average Nusselt number. The duration of the transient increases with the increment of the Ekman number and disk thickness, and the reduction in the thermal diffusivity of the disk material.

Flow Structure and Heat Transfer During Free Liquid Jet Impingement Over a Rotating Disk

2005 ◽  
Author(s):  
Jorge Lallave ◽  
Muhammad M. Rahman
Keyword(s):  
Heat Transfer ◽  
Nusselt Number ◽  
Flow Structure ◽  
Local Nusselt Number ◽  
Jet Impingement ◽  
Rotating Disk ◽  
Liquid Jet ◽  
Fluid Interface ◽  
Rotational Rate ◽  
Wafer Thickness

The aim of this computational study was to characterize the flow structure and convective heat transfer for a free liquid jet impinging on a rotating and uniformly heated solid wafer of finite thickness and radius. The main focus considered was the effect of cooling by adding a secondary rotational flow with jet impingement. The model covers the entire fluid region (impinging jet and flow spreading out over the rotating surface) and the solid disk as a conjugate problem. Calculations were done for various standard microelectronics materials, namely aluminum, copper, silver, Constantan, and silicon; at Reynolds number ranging from 445 to 1800, under a broad rotational rate range from 125 to 6000 rpm, and range of wafer thickness from 0.2 to 2 mm, respectively. The working fluids used for this simulation included water (H2O), ammonia (NH3), flouroinert (FC-77), and (MIL-7808) oil. In the present work only laminar liquid flow was considered for Ekman number range from 5.52 × 10−6 to 2.65 × 10−4. The nozzle to disk radius ratio (rd/dn) of 6.333 was kept constant for this study. Plate materials with higher thermal conductivity maintained a more uniform temperature distribution at the solid-fluid interface. Higher Reynolds numbers increased the Nusselt number and local heat transfer coefficient distributions reducing the wall to fluid temperature difference over the entire interface. In general, the rotational rate increases the local Nusselt number values over the entire solid-fluid interface. However, at high rate of rotation, the local Nusselt number decreases because the fluid tends to separate from the rotating disk surface. It was also found that wafer thickness beyond 1 mm did not change significantly the average solid-fluid dimensionless interface temperature and Nusselt number distributions.

Liquid Jet Impingement Cooling of a Rotating Disk

1986 ◽  
Vol 108 (3) ◽  
pp. 540-546 ◽  
Author(s):  
H. J. Carper ◽  
J. J. Saavedra ◽  
T. Suwanprateep
Keyword(s):  
Reynolds Number ◽  
Average Nusselt Number ◽  
Convective Heat Transfer Coefficient ◽  
Jet Impingement ◽  
Rotating Disk ◽  
Liquid Jet ◽  
Flow Rates ◽  
Impingement Cooling ◽  
Angular Velocities ◽  
Jet Nozzle

Results are presented from an experimental study conducted to determine the average convective heat transfer coefficient for the side of a rotating disk, with an approximately uniform surface temperature, cooled by a single liquid jet of oil impinging normal to the surface. Tests were conducted over a range of jet flow rates, jet temperatures, jet radial positions, and disk angular velocities with various combinations of three jet nozzle and disk diameters. Correlations are presented that relate the average Nusselt number to rotational Reynolds number, jet Reynolds number, jet Prandtl number, and dimensionless jet radial position.

Jet Cooling at the Rim of a Rotating Disk

1979 ◽  
Vol 101 (1) ◽  
pp. 68-72 ◽  
Author(s):  
D. E. Metzger ◽  
W. J. Mathis ◽  
L. D. Grochowsky
Keyword(s):  
Heat Transfer ◽  
Experimental Study ◽  
Jet Impingement ◽  
Rotating Disk ◽  
Impinging Jets ◽  
Turbine Engine ◽  
Transfer Rates ◽  
Jet Cooling ◽  
Geometric Conditions ◽  
Face Contour

Results are presented from an experimental study conducted to measure heat transfer rates at the rim of a rotating disk convectively cooled by impinging jets. The disk face contour radially inward from the rim is varied to simulate the geometric conditions found on gas turbine engine rotors. Heat transfer rates are found to be relatively unaffected by impingement for jet flowrates less than the order of one-tenth the disk pumping flow. Disk pumping flows are evaluated through the use of an analysis which accounts for the presence of the disk hub. At larger jet flowrates, heat transfer rates increase strongly with increasing jet flow, reaching two to three times the no-impingement values at jet flowrates approximately equal to the pumped flow. All the heat transfer results, both with and without jet impingement, are essentially unaffected by changes in the disk face contour.

scholarly journals Heat transfer during pulsating liquid jet impingement onto a vertical wall

2020 ◽  
Author(s):  
J. Wassenberg ◽  
P. Stephan ◽  
T. Gambaryan-Roisman
Keyword(s):  
Heat Transfer ◽  
Vertical Wall ◽  
Jet Impingement ◽  
High Heat ◽  
Heated Wall ◽  
Liquid Jet ◽  
Pulsation Frequency ◽  
Cooling Efficiency ◽  
Heat Transfer Efficiency ◽  
Impingement Point

Abstract Liquid jet impingement is used for cooling and cleaning in various industrial branches. The advantages of jet impingement include high heat and mass transport rates in the vicinity of the impingement point. Pulsating liquid jets impinging on horizontal substrates with a pulsation frequency around 100 Hz have been shown to increase the cooling efficiency in comparison to jets with continuous mass flow rates. The influence of jet pulsation on cooling efficiency for impingement of horizontal jets onto vertical walls has not yet been investigated. In the case of a vertical heated wall, gravity contributes to the liquid flow pattern. In particular, if the time span between two pulses is sufficiently long, the liquid drainage from the region above the impingement point can contribute to heat transport without increasing the average flow rate of the cooling medium. In this work, the influence of pulsations on heat transfer during impingement of a horizontal liquid jet onto a vertical wall is investigated experimentally for the pulsation frequency range 1–5 Hz. The results regarding increase of heat transfer efficiency are related to flow patterns developing by impingement of successive pulses, as well as to the liquid splattering.

Confined Liquid Jet Impingement on a Plate With Discrete Heating Elements

2005 ◽  
Author(s):  
Muhammad M. Rahman ◽  
Santosh K. Mukka
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Jet Impingement ◽  
Liquid Jet ◽  
Heat Sources ◽  
Average Heat Transfer Coefficient ◽  
Average Heat ◽  
Discrete Heat Sources ◽  
Solid Region

The primary focus of this paper is the conjugate heat transfer during vertical impingement of a two-dimensional (slot) submerged confined liquid jet using liquid ammonia as the working fluid. Numerical model for the heat transfer process has been developed. The solid region has been modeled along with the fluid region as a conjugate problem. Discrete heat sources have been used to study the overall effect on convective heat transfer. Simulation of discrete heat sources was done by introducing localized heat fluxes at various locations and their magnitudes being varied. Simulations are performed for two different substrate materials namely silicon and stainless steel. The equations solved in the liquid region included the conservation of mass, conservation of momentum, and conservation of energy. In the solid region, only the energy equation, which reduced to the heat conduction equation, had to be solved. The solid-fluid interface temperature showed a strong dependence on several geometric, fluid flow, and heat transfer parameters. The Nusselt number increased with Reynolds number. For a given flow rate, a higher heat transfer coefficient was obtained with smaller slot width and lower impingement height. For a constant Reynolds number, jet impingement height and plate thickness, a wider opening of the slot provided higher average heat transfer coefficient and higher average Nusselt number. A higher average heat transfer coefficient was seen at a smaller thickness, whereas a thicker plate provided a more uniform distribution of heat transfer coefficient. Higher thermal conductivity substrates also provided a more uniform heat distribution.

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