Flow Structures and Heat Transfer on Small-Scale Concentric Ribs Rough Surface for Confined Turbulent Jet Impingement

2021 ◽  
Author(s):  
Guiyong Zhang ◽  
Huakun Huang ◽  
Tiezhi Sun ◽  
Zhifan Zhang
Keyword(s):  
Heat Transfer ◽  
Rough Surface ◽  
Jet Impingement ◽  
Turbulent Jet ◽  
Flow Structures ◽  
Small Scale

Submerged Jet Impingement Cooling of a Nanostructured Plate

2010 ◽  
Author(s):  
Muhsincan Sesen ◽  
Ali Kosar ◽  
Ebru Demir ◽  
Evrim Kurtoglu ◽  
Nazli Kaplan ◽  
...  
Keyword(s):  
Thin Film ◽  
Heat Transfer ◽  
Heat Flux ◽  
Silicon Wafer ◽  
Heat Removal ◽  
Jet Impingement ◽  
Wafer Surface ◽  
Small Scale ◽  
Copper Thin Film ◽  
Thin Film Layer

In this paper, the results of a series of heat transfer experiments conducted on a compact electronics cooling device based on single phase jet impingement techniques are reported. Deionized-water is propelled into four microchannels of inner diameter 685 μm which are used as nozzles and located at a nozzle to surface distance of 2.5mm. The generated jet impingement is targeted through these channels towards the surface of a nanostructured plate. This plate of size 20mmx20mm consisted of ∼600 nm long copper nanorod arrays with an average nanorod diameter of ∼150 nm, which were integrated on top of a silicon wafer substrate coated with a copper thin film layer (i.e. Cu-nanorod/Cu-film/Silicon-wafer). Heat removal characteristics induced through jet impingement are investigated using the nanostructured plate and compared to results obtained from a flat plate of copper thin film coated on silicon wafer surface. Enhancement in heat transfer up to 15% using the nanostructured plate has been reported in this paper. Heat generated by small scale electronic devices is simulated using a thin film heater placed on an aluminum base. Surface temperatures are recorded by a data acquisition system with the thermocouples integrated on the surface at various locations. Constant heat flux provided by the film heater is delivered to the nanostructured plate placed on top of the base. Volumetric flow rate and heat flux values were varied in order to better characterize the potential enhancement in heat transfer by nanostructured surfaces.

Performance Assessment of Single and Multiple Jet Impingement Configurations in a Refrigeration-Based Compact Heat Sink for Electronics Cooling

2017 ◽  
Vol 139 (3) ◽  
Author(s):  
Pablo A. de Oliveira ◽  
Jader R. Barbosa
Keyword(s):  
Heat Transfer ◽  
Heat Sink ◽  
Cooling System ◽  
Electronics Cooling ◽  
Jet Impingement ◽  
Small Scale ◽  
Two Phase ◽  
R 134A ◽  
Steady State Heat Transfer ◽  
Vapor Compression Cooling

The performance of a novel impinging two-phase jet heat sink operating with single and multiple jets is presented and the influence of the following parameters is quantified: (i) thermal load applied on the heat sink and (ii) geometrical arrangement of the orifices (jets). The heat sink is part of a vapor compression cooling system equipped with an R-134a small-scale oil-free linear motor compressor. The evaporator and the expansion device are integrated into a single cooling unit. The expansion device can be a single orifice or an array of orifices responsible for the generation of two-phase jet(s) impinging on a surface where a concentrated heat load is applied. The analysis is based on the thermodynamic performance and steady-state heat transfer parameters associated with the impinging jet(s) for single and multiple orifice tests. The two-phase jet heat sink was capable of dissipating cooling loads of up to 160 W and 200 W from a 6.36 cm2 surface for single and multiple orifice configurations, respectively. For these cases, the temperature of the impingement surface was kept below 40 °C and the average heat transfer coefficient reached values between 14,000 and 16,000 W/(m2 K).

Recent Trends in Computation of Turbulent Jet Impingement Heat Transfer

2012 ◽  
Vol 33 (4-5) ◽  
pp. 447-460 ◽  
Author(s):  
Anupam Dewan ◽  
Rabijit Dutta ◽  
Balaji Srinivasan
Keyword(s):  
Heat Transfer ◽  
Jet Impingement ◽  
Turbulent Jet ◽  
Impingement Heat Transfer ◽  
Recent Trends

Predicting Heat Transfer From Unsteady Synthetic Jets

2012 ◽  
Vol 134 (8) ◽  
Author(s):  
Mehmet Arik ◽  
Tunc Icoz
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Jet Impingement ◽  
Synthetic Jet ◽  
Synthetic Jets ◽  
Operating Conditions ◽  
Small Scale ◽  
Wide Range ◽  
The Heat Transfer Coefficient

Synthetic jets are piezo-driven, small-scale, pulsating devices capable of producing highly turbulent jets formed by periodic entrainment and expulsion of the fluid in which they are embedded. The compactness of these devices accompanied by high air velocities provides an exciting opportunity to significantly reduce the size of thermal management systems in electronic packages. A number of researchers have shown the implementations of synthetic jets on heat transfer applications; however, there exists no correlation to analytically predict the heat transfer coefficient for such applications. A closed form correlation was developed to predict the heat transfer coefficient as a function of jet geometry, position, and operating conditions for impinging flow based on experimental data. The proposed correlation was shown to predict the synthetic jet impingement heat transfer within 25% accuracy for a wide range of operating conditions and geometrical variables.

Heat Transfer From a Heated Flat Surface due to Swirling Coaxial Turbulent Jet Impingement

2020 ◽  
Vol 13 (2) ◽  
Author(s):  
Farhana Afroz ◽  
Muhammad A.R. Sharif
Keyword(s):  
Heat Transfer ◽  
Flat Surface ◽  
Heated Surface ◽  
Jet Impingement ◽  
Target Surface ◽  
Separation Distance ◽  
Heat Transfer Process ◽  
Turbulent Jet ◽  
Impingement Surface ◽  
Outer Pipe

Abstract Heat transfer from an isothermally hot flat surface due to swirling coaxial turbulent jet impingement is investigated numerically. The coaxial jet construction consists of implanting a thin-walled round tube inside a coaxial outer pipe. Two different fluid streams or jets, having different average velocities, flow through the inner tube, and the annular space between the inner tube and the outer pipe. The ratio of the average velocities of the jets, the ratio of the pipe diameters, the jet exit Reynolds number, the strength of the swirl, and the separation distance from the jet exit to the impingement surface are the main parameters for this flow configuration. The effects of the swirl strength on the jet impingement heat transfer at the target surface are investigated by computing the flow and thermal fields for various combinations of the problem parameters. The presented results contain the plots of the flow streamlines, the contours of the temperature, the contours of the swirl velocity, as well as the distribution of the local and average Nusselt number on the impingement surface. It is found that, compared to the single round jet, the coaxial jet produces enhanced and more uniform heat transfer at the heated surface. The jet-spreading and mixing are affected by the imposed jet swirl which modifies the heat transfer process. Thus, the heat transfer compared to a non-swirling jet is either enhanced or diminished depending on the combination of the problem parameters.

FLOW STRUCTURES AND HEAT TRANSFER IN SUBMERGED LAMINAR JET IMPINGEMENT

2016 ◽  
Author(s):  
Wilko Rohlfs ◽  
Johannes Jorg ◽  
Claas Ehrenpreis ◽  
Manuel Rietz ◽  
Herman D. Haustein ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Jet Impingement ◽  
Flow Structures ◽  
Laminar Jet

Heat transfer and entropy generation in air jet impingement on a model rough surface

2016 ◽  
Vol 72 ◽  
pp. 48-56 ◽  
Author(s):  
Peng Xu ◽  
Agus P. Sasmito ◽  
Shuxia Qiu ◽  
Arun S. Mujumdar ◽  
Long Xu ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Rough Surface ◽  
Entropy Generation ◽  
Jet Impingement ◽  
Air Jet
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