scholarly journals Fin Efficiency Design of Micro-Channel for Nd: YAG Slab Laser

2020 ◽  
Vol 8 (2S12) ◽  
pp. 107-110
Keyword(s):  
Heat Dissipation ◽  
Thermal Distortion ◽  
Micro Channel ◽  
Water Cooling ◽  
Fin Efficiency ◽  
Slab Laser ◽  
The Heat Transfer Coefficient ◽  
Very High ◽  
High Range ◽  
Slab Lasers

The heat generated by a Slab Lasers can exceed 1,000 watts but the area available for cooling is too small. This results in localization of heat flux which makes heat dissipation a challenge in slab lasers. The Heat transfer coefficient can increase up to a very high range, which can’t be efficiently achieved by the conventional water cooling. Micro-channel coolers address this problem competently. These channels contain liquid, which transfers heat to the sink with high efficiency.The objective of this paper is to design the microchannel coolers that will be efficiently capable of removing the heat from the slab laser without causing any thermal distortion in the laser. The dimension of the slab is given as follows:-Length(l) =50mm, Width(w) =8mm and thickness(t)=2mm.

Design and Tests of a Water-Cooling Micro-Channel Heat Sink Made by WEDM

2012 ◽  
Vol 459 ◽  
pp. 609-614
Author(s):  
Kuo Zoo Liang ◽  
A Cheng Wang ◽  
Chun Ho Liu ◽  
Lung Tasi ◽  
Yan Cherng Lin
Keyword(s):  
Thermal Resistance ◽  
Heat Sink ◽  
Electrical Discharge ◽  
Heat Dissipation ◽  
Electrical Discharge Machining ◽  
Input Power ◽  
Wire Electrical Discharge Machining ◽  
Micro Channel ◽  
Water Cooling ◽  
Computer Aided

The purpose of this research is to design a new heat sink of water-cooling. With the aid of CAE (computer aided engineering), WEDM (wire electrical discharge machining), and the concept of micro-channel design, a heat sink of water-cooling can then be built with the merit of a smaller volume and lower thermal resistance. From this paper, results of the experiment indicate that the thermal resistance of heat sink can be decreased to 0.12 °C/W with input power of 60W, flow rate of 0.6 LPM, and a better heat dissipation with the in input power of 100W or 140W can be revealed.

scholarly journals The Comparison of Water Cooling Media Against Radiator Heat Dissipation Rate in Diesel Engines

2021 ◽  
Vol 3 (1) ◽  
pp. 19-26
Author(s):  
Muhammad Sawaludin ◽  
Hasan Maksum ◽  
Wagino Wagino
Keyword(s):  
Experimental Research ◽  
Diesel Engines ◽  
Heat Dissipation ◽  
Statistical Tests ◽  
Working Fluid ◽  
Research Approach ◽  
Water Cooling ◽  
Average Decrease ◽  
Cooling Media ◽  
The Heat Transfer Coefficient

This research was motivated by the large number of consumer requests for mechanics in workshops to replace the radiator coolant in diesel engines with reguler water. This research used an experimental research approach. The experimental research was often used to find the effect of existing variable and to test the hypotheses. Based on the results of testing and data analysis that have been carried out can be seen: there was an average decrease in the temperature of the cooling media from the engine due to using the cooling media from the manufacturer, a decrease in the rate of heat dissipation between reguler water and Prestone on each rotation with an average of 4.97%, the water with TOP 1 Coolant 5.11% and the water with Toyota SLCC at 6.64%. Based on the analysis of research data and statistical tests, it was concluded that the use of cooling media from the manufacturer can increase the heat transfer coefficient of the working fluid of the radiator, so that it can reduce the engine heat level and increase the rate of coolant heat dissipation. Penelitian ini dilatarbelakangi oleh banyaknya permintaan konsumen kepada mekanik di bengkel untuk mengganti air radiator pada mesin diesel dengan air biasa Penelitian ini digolongkan pada penelitian pendekatan eksperimen. Penelitian eksperimen sering digunakan untuk mencari pengaruh di antara variabel-variabel yang ada serta untuk pengujian hipotesis. Hasil pengujian dan analisis data yang telah dilakukan dapat diketahui: Terdapat rata-rata penurunan suhu media pendingin dari mesin akibat menggunakan media pendingin asal pabrikan, penurunan laju pembuangan panas antara air biasa dengan Prestone pada masing-masing putaran dengan rata-rata 4,97%, air dengan TOP 1 Coolant 5,11% dan air dengan Toyota SLCC sebesar 6,64%. Berdasarkan analisis data penelitian dan uji statistik yang dilakukan disimpulkan bahwa penggunaan media pendingin asal pabrikan dapat memperbesar koefisien perpindahan panas fluida kerja radiator sehingga dapat menurunkan tingkat panas mesin dan meningkatkan laju pembuangan panas cairan pendingin

scholarly journals Water Cooling Pipe Structure for Heat-Dissipation of HEV Inverter System

2010 ◽  
Vol 15 (1) ◽  
pp. 27-34 ◽  
Author(s):  
Gyoung-Man Kim ◽  
Byung-Guk Woo ◽  
Yong-Hwa Lee ◽  
Chan-Ho Kang ◽  
Tae-Won Chun ◽  
...  
Keyword(s):  
Heat Dissipation ◽  
Water Cooling ◽  
Cooling Pipe

Regional study of orogenic ultramafics of the Seve Nappe Complex, Scandinavian Caledonides - preliminary results from northern and central Jämtland, Sweden

2021 ◽  
Author(s):  
Daniel Buczko ◽  
Magdalena Matusiak-Małek ◽  
Jarosław Majka ◽  
Iwona Klonowska ◽  
Grzegorz Ziemniak
Keyword(s):  
Preliminary Data ◽  
Regional Study ◽  
Scandinavian Caledonides ◽  
Nappe Complex ◽  
Science Centre ◽  
Seve Nappe Complex ◽  
End Members ◽  
Very High ◽  
Different Levels ◽  
High Range

<p>The Scandinavian Caledonides comprise numerous ultramafic bodies emplaced within metamorphic nappe complexes. A hypothetical suture between the most distal crustal units representing Baltican margin (Seve Nappe Complex, SNC) with the oceanic Iapetian terranes (Köli Nappe Complex) is abundant in such occurrences. Here we present preliminary data on garnet/spinel peridotites/pyroxenites from SNC in central and northern parts of Swedish Jämtland county. The presented results are a part of a project involving regional study focused on orogenic peridotites (mostly spinel-bearing) of Seve and Köli nappe complexes. </p><p>The ultramafic bodies in the study area range from a meters to kilometer scale and comprise: 1) garnet peridotites, 2) spinel peridotites, 3) spinel pyroxenites and 4) garnet pyroxenites. Individual outcrops often record different levels of serpentinisation. </p><p>The Grt-peridotites are usually harzburgites (sparsely dunites/lherzolites) with an assemblage of Ol+Opx+Cpx+Amph+Grt+Spl.  Minerals within the Grt-peridotites are characterised by Ol Fo=~90-91 and Mg# in pyroxenes 90-92 and 92-96 (enstatite and diopside/Cr-diopside, respectively). Garnet is pyrope with end-members Prp=60-69%, Usp=0-4% and Cr#=0.5-4. Amphibole (pargasite; Mg#=88-92) typically occurs as patches or rims around Grt and often host significant amounts of Spl. The spinel has an intermediate composition between hercynite-spinel and magnesiochromite-chromite (Cr#=41-55, Mg#=40-57). </p><p>The spinel peridotites are formed of Ol+Opx+Amph+Chl+Spl and classify mostly as harzburgites/dunites. Olivine and Opx (enstatite, rarely Cr-enstatite; often as porphyrocrysts) show a high range of Fo/Mg# values (90-95 and 90-94, respectively). Amphibole (tremolite; Mg#=91-96) is usually evenly distributed within the rock, while Chl is often associated with grain boundaries. Spinel has a chromite composition (Cr#=82-100, Mg#=5-10). Within single large (~0.5mm) spinel grains, cores with higher Mg# (~23) and lower Cr# (~82) can be observed.</p><p>The garnet pyroxenites are websterites characterised by lower Mg# (88-90) in enstatite, presence of Al-diopside and lower Cr# (<0.5) in pyrope than in peridotites. The Spl-pyroxenites are orthopyroxenites with Mg# in enstatite (86-88) lower than in peridotitic orthopyroxene.</p><p>The presented preliminary data suggest that lithologies formed under different pressures (i.e. Grt and Spl facies) and must have recorded different evolution paths. Garnet ultramafics mineralogy resembles typical “mantle” assemblage with Prg suggesting possible metamorphic input also for other consisting phases (similarly to M2 paragenesis described in [1]). While the Grt ultramafic rocks and their evolution has been a subject of several studies before, the Spl ultramafics are relatively understudied and can shed new light on the evolution of SNC. The composition of Spl peridotites represents a mixture of typical “magmatic” mantle phases with metamorphic minerals (Amph+Chl). Very high Mg# values and occurrence of 120° triple point junctions in Ol (also described in [2]) suggest complex genesis, which probably includes serpentinisation (+exhumation?) followed by deserpentinisation. This indicates that the Spl ultramafics of SNC might have been subducted after their primary serpentinisation, which can be related either to emplacement and exhumation of ultramafics during Rodinia breakup or derivation from shallow, serpentinised “wet” mantle wedge in the subduction zone. </p><p>Research founded by Polish National Science Centre grant no. 2019/35/N/ST10/00519.</p><p>[1] Gilio et al. (2015). Lithos 230, 1-16.<br>[2] Clos et al. (2014). Lithos 192-195, 8-20.</p>

scholarly journals Experimental and Simulation Study of Micro-Channel Backplane Heat Pipe Air Conditioning System in Data Center

2020 ◽  
Vol 10 (4) ◽  
pp. 1255
Author(s):  
Liping Zeng ◽  
Xing Liu ◽  
Quan Zhang ◽  
Jun Yi ◽  
Xiaohua Li ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Pressure Drop ◽  
Transfer Coefficient ◽  
Heat Transfer Performance ◽  
Outlet Temperature ◽  
Transfer Performance ◽  
Micro Channel ◽  
Heat Transfer Capacity ◽  
The Heat Transfer Coefficient

This paper mainly studies the heat transfer performance of backplane micro-channel heat pipes by establishing a steady-state numerical model. Compared with the experimental data, the heat transfer characteristics under different structure parameters and operating parameters were studied, and the change of heat transfer coefficient inside the system, the air outlet temperature of the back plate and the influence of different environmental factors on the heat transfer performance of the system were analyzed. The results show that the overall error between simulation results and experimental data is less than 10%. In the range of the optimal filling rate (FR = 64.40%–73.60%), the outlet temperature at the lowest point and the highest point of the evaporation section is 22.46 °C and 19.60 °C, the temperature difference does not exceed 3 °C, and the distribution gradient in vertical height is small and the air outlet temperature is uniform. The heat transfer coefficient between the evaporator and the condenser is larger than the heat transfer coefficient under the conditions of low and high liquid charge rate. It increases gradually along the flow direction, and decreases gradually with the flow rate of the condenser. When the width of the flat tube of the evaporator increases from 20 mm to 28 mm, the internal pressure drop of the evaporator decreases by 45.83% and the heat exchange increases by 18.34%. When the number of evaporator slices increases from 16 to 24, the heat transfer increases first and then decreases, with an overall decrease of 2.86% and an increase of 87.67% in the internal pressure drop of the evaporator. The inclination angle of the corrugation changes from 30° to 60°, and the heat transfer capacity and pressure drop increase. After the inclination angle is greater than 60°, the heat transfer capacity and resistance decrease. The results are of great significance to system optimization design and engineering practical application.

Understanding the True Total Cost of Ownership of Water Cooling for Data Centers

2015 ◽  
Author(s):  
Dustin W. Demetriou ◽  
Vinod Kamath ◽  
Howard Mahaney
Keyword(s):  
Data Center ◽  
Data Centers ◽  
Heat Dissipation ◽  
Cost Effective ◽  
Electric Utility ◽  
Air Cooling ◽  
Water Cooling ◽  
Total Cost Of Ownership ◽  
Total Cost ◽  
Cost Of Ownership

The generation-to-generation IT performance and density demands continue to drive innovation in data center cooling technologies. For many applications, the ability to efficiently deliver cooling via traditional chilled air cooling approaches has become inadequate. Water cooling has been used in data centers for more than 50 years to improve heat dissipation, boost performance and increase efficiency. While water cooling can undoubtedly have a higher initial capital cost, water cooling can be very cost effective when looking at the true lifecycle cost of a water cooled data center. This study aims at addressing how one should evaluate the true total cost of ownership for water cooled data centers by considering the combined capital and operational cost for both the IT systems and the data center facility. It compares several metrics, including return-on-investment for three cooling technologies: traditional air cooling, rack-level cooling using rear door heat exchangers and direct water cooling via cold plates. The results highlight several important variables, namely, IT power, data center location, site electric utility cost, and construction costs and how each of these influence the total cost of ownership of water cooling. The study further looks at implementing water cooling as part of a new data center construction project versus a retrofit or upgrade into an existing data center facility.

scholarly journals Experimental Investigation of Flow Condensation in Microgravity

2013 ◽  
Author(s):  
Hyoungsoon Lee ◽  
Ilchung Park ◽  
Christopher Konishi ◽  
Issam Mudawar ◽  
Rochelle I. May ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Heat Dissipation ◽  
Flow Boiling ◽  
Condensation Heat Transfer ◽  
Interfacial Structure ◽  
Sensible Heat ◽  
Two Phase ◽  
The Heat Transfer Coefficient

Future manned missions to Mars are expected to greatly increase the space vehicle’s size, weight, and heat dissipation requirements. An effective means to reducing both size and weight is to replace single-phase thermal management systems with two-phase counterparts that capitalize upon both latent and sensible heat of the coolant rather than sensible heat alone. This shift is expected to yield orders of magnitude enhancements in flow boiling and condensation heat transfer coefficients. A major challenge to this shift is a lack of reliable tools for accurate prediction of two-phase pressure drop and heat transfer coefficient in reduced gravity. Developing such tools will require a sophisticated experimental facility to enable investigators to perform both flow boiling and condensation experiments in microgravity in pursuit of reliable databases. This study will discuss the development of the Flow Boiling and Condensation Experiment (FBCE) for the International Space Station (ISS), which was initiated in 2012 in collaboration between Purdue University and NASA Glenn Research Center. This facility was recently tested in parabolic flight to acquire condensation data for FC-72 in microgravity, aided by high-speed video analysis of interfacial structure of the condensation film. The condensation is achieved by rejecting heat to a counter flow of water, and experiments were performed at different mass velocities of FC-72 and water and different FC-72 inlet qualities. It is shown that the film flow varies from smooth-laminar to wavy-laminar and ultimately turbulent with increasing FC-72 mass velocity. The heat transfer coefficient is highest near the inlet of the condensation tube, where the film is thinnest, and decreases monotonically along the tube, except for high FC-72 mass velocities, where the heat transfer coefficient is enhanced downstream. This enhancement is attributed to both turbulence and increased interfacial waviness. One-ge correlations are shown to predict the average condensation heat transfer coefficient with varying degrees of success, and a recent correlation is identified for its superior predictive capability, evidenced by a mean absolute error of 21.7%.

A Novel Magnetorheological Concentric Spiral-Flow Damper

2015 ◽  
Author(s):  
Kai Hsiang Chang ◽  
Jing Long Tong ◽  
Chou Min Chia ◽  
Kuang Yuh Huang
Keyword(s):  
Heat Dissipation ◽  
Experimental Studies ◽  
Low Frequency ◽  
Mr Damper ◽  
Flow Channel ◽  
Spiral Flow ◽  
Damping Force ◽  
Fixed Space ◽  
Novel Design ◽  
High Range

In this article, a novel design of MR damper, concentric spiral flow MR damper, is proposed. It could improve the heat dissipation problem which is usually found in traditional MR damper. The proposed MR damper has a concentric spiral flow channel around the cylinder which not only separates coils from MR fluid, but also increases the length of flow channel in a fixed space. Experimental studies has been conducted to demonstrate the performance of the proposed MR damper, the result shows the MR damper generates the maximum damping force of 188 N without applying magnetic field and 1251 N when inputting 1.5 A at low frequency, which means the damper has high range of adjustable damping force. The CSF-damper can be used to systems or structures with low dynamic response.

scholarly journals Targeted cooling with CVD diamond and micro-channel to meet 3-D IC heat dissipation challenge

2012 ◽  
Author(s):  
Aftab Alam Khan ◽  
Shabaz Basheer Patel ◽  
Divanshu Chaturvedi ◽  
Ashudeb Dutta ◽  
Shivgovind Singh
Keyword(s):  
Heat Dissipation ◽  
Cvd Diamond ◽  
Micro Channel

Inter-age correlations of body weight, weight gain and food intake within and between breeds of cattle

1985 ◽  
Vol 40 (1) ◽  
pp. 23-32 ◽  
Author(s):  
R. B. Thiessen
Keyword(s):  
Body Weight ◽  
Weight Gain ◽  
Food Intake ◽  
Daily Intake ◽  
Average Daily Intake ◽  
Daily Food ◽  
Ad Libitum ◽  
Pelleted Diet ◽  
Very High ◽  
High Range

ABSTRACTIn a multibreed experiment, 292 heifers from 25 British cattle breeds were fed a standard pelleted diet ad libitum from 12 to 72 weeks of age. Inter-age correlations involving body weight, weight gain, average daily food intake and cumulated food intake were measured across traits at the same age and within and across traits at ages separated by an interval of 12, 24, 36 and 48 weeks. Within-breed correlations were phenotypic but between-breed correlations were genetic.The between-breed inter-age correlations involving body weight, cumulated intake and average daily intake were all very high (range 104 to 0·94) and declined only gradually as the intervening age interval increased from 12 to 48 weeks. Inter-age correlations involving weight gain were lower but usually above 0·7. The within-breed correlations by contrast were invariably lower and declined much more rapidly as the age interval increased. Although the between-breed and within-breed correlations differed in magnitude there was a similarity in their overall pattern.For breed samples, body weight at young ages provided very accurate rankings at later ages for body weight, cumulated intake and average daily intake. Body weight was almost as reliable as food intake itself for predicting cumulated intake.For individuals within breeds predicted rankings at later ages were not very accurate for body weight or cumulated intake and they became worse as the age interval increased. Neither weight gain nor average daily intake could be predicted with any reliability.Inter-age correlations while dependant on age interval did not depend on age itself in the case of body weight and cumulated intake, although they were age-dependant for weight gain and to a lesser extent for average daily intake. Reciprocal correlations between body weight and cumulated intake were very symmetrical whereas those involving weight gain and daily intake were asymmetrical.

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