Heat Transfer Analysis of Supercritical Methane in Microchannels with Different Geometric Configurations On High Power Electromechanical Actuator

2022 ◽  
Author(s):  
Zhigang Gao ◽  
Tianhu Wang ◽  
Yuxin Yang ◽  
Xiaolong Shang ◽  
Junhua Bai ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Thermal Performance ◽  
High Power ◽  
Heat Sink ◽  
Heat Removal ◽  
Electrical Equipment ◽  
Heat Sinks ◽  
Electromechanical Actuator ◽  
Regenerative Cooling ◽  
Geometric Configurations

Abstract The issue of regenerative cooling is one of the most important key technologies of flight vehicles, which is applied into both the engine and high-power electrical equipment. One pattern of regenerative cooling channels is the microchannel heat sinks, which are thought as a prospective means of improving heat removal capacities on electrical equipment of smaller sizes. In this paper, three numerical models with different geometric configurations, namely straight, zigzag, and sinusoid respectively, are built to probe into the thermal hydraulic performance while heat transfer mechanism of supercritical methane in microchannel heat sinks for the heat removal of high-power electromechanical actuator is also explored. In addition, some crucial influence factors on heat transfer such as inlet Reynolds number, operating pressure and heating power are investigated. The calculation results imply the positive effect of wavy configurations on heat transfer and confirm the important effect of buoyancy force of supercritical methane in channels. The heat sinks with wavy channel show obvious advantages on comprehensive thermal performance including overall thermal performance parameter ? and thermal resistance R compared with that of the straight one. The highest Nu and average heat transfer coefficient am appear in the heat sink with zigzag channels, but the pumping power of the heat sink with sinusoidal channels is lower due to the smaller flow loss.

High Power CPU Cooling Experiment

1995 ◽  
Author(s):  
Elizabeth B. Nadworny ◽  
T. Gary Yip ◽  
Nader Farag
Keyword(s):  
Heat Transfer ◽  
High Power ◽  
Power Dissipation ◽  
Heat Removal ◽  
Data Acquisition System ◽  
Heat Sinks ◽  
Small Scale ◽  
Heat Transfer Area ◽  
Pin Fin ◽  
Transfer Parameters

Abstract This experimental study focuses on the enhancement of the heat removal process by modifying the geometry of pin fin heat sinks, while maintaining the same effective heat transfer area. The pins are cut at an angle to reduce the blockage of air flow across the surface. To perform this study, a small scale wind tunnel facility has been designed specifically for testing high power dissipation processors and other ULSI components. The facility is fully automated and controlled by an HP3852A Data Acquisition System interfaced with a 486 based PC computer. The average surface temperature, Reynolds number, Nusselt number and other relevant heat transfer parameters were reduced from the data collected. Results from the study show that a heat sink with an angled trailing edge produces the greatest enhancement of heat removal. The mechanism for the improved heat transfer is the larger temperature gradient across the surface, which is obtained by lowering the minimum temperature on the surface.

Computational fluid dynamics for thermal performance of a water-cooled minichannel heat sink with different chip arrangements

2014 ◽  
Vol 24 (4) ◽  
pp. 797-810 ◽  
Author(s):  
Gongnan Xie ◽  
Shian Li ◽  
Bengt Sunden ◽  
Weihong Zhang
Keyword(s):  
Heat Transfer ◽  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Thermal Performance ◽  
Heat Sink ◽  
Electronic Devices ◽  
Heat Sinks ◽  
Bottom Surface ◽  
Moderate Pressure ◽  
Content Type

Purpose – With the development of electronic devices, including the desires of integration, miniaturization, high performance and the output power, cooling requirement of chips have been increased gradually. Water-cooled minichannel is an effective cooling technology for cooling of heat sinks. The minichannel flow geometry offers large surface area for heat transfer and a high convective heat transfer coefficient with only a moderate pressure loss. The purpose of this paper is to analyze a minichannel heat sink having the bottom size of 35 mm×35 mm numerically. Two kinds of chip arrangement are investigated: diagonal arrangement and parallel arrangement. Design/methodology/approach – Computational fluid dynamics (CFD) technique is used to investigate the flow and thermal fields in forced convection in a three-dimensional minichannels heat sink with different chip arrangements. The standard k-e turbulence model is applied for the turbulence simulations on the minichannel heat sink. Findings – The results show that the bottom surface of the heat sink with various chip arrangements will have different temperature distribution and thermal resistance. A suitable chip arrangement will achieve a good cooling performance for electronic devices. Research limitations/implications – The fluid is incompressible and the thermophysical properties are constant. Practical implications – New and additional data will be helpful as guidelines in the design of heat sinks to achieve a good thermal performance and a long lifetime in operation. Originality/value – In real engineering situations, chips are always placed in various manners according to design conditions and constraints. In this case the assumption of uniform heat flux is acceptable for the surfaces of the chips rather than for the entire bottom surface of the heat sink.

An Experimental Study on the Effect of Configuration of Multiple Microchannels on Heat Removal for Electronic Cooling

2010 ◽  
Author(s):  
Jingru Zhang ◽  
Shaurya Prakash ◽  
Yogesh Jaluria ◽  
Lei Lin
Keyword(s):  
Heat Transfer ◽  
Heat Sink ◽  
Heat Removal ◽  
Electronic Cooling ◽  
Heat Sinks ◽  
Flow Loop ◽  
Labview Software ◽  
Chemical Etch ◽  
Potential Applications

This paper presents the design, fabrication, and characterization of three different configurations of multiple microchannel heat sink devices to improve their overall cooling efficiency for potential applications in electronic cooling. A fabrication and packaging process based on standard UV-lithography, wet etching, and bonding was developed to allow a rapid parametric study. An anisotropic chemical etch with potassium hydroxide, water, and isopropanol is used to fabricate microchannels on (110)-oriented silicon wafers. PDMS (Polydimethylsiloxane) was tested as the cover of microchannels due to its mechanical flexibility. It is transparent so that the microchannel flow can be visualized using a microscope. An open flow loop, which consists of syringe pump and a power supply, was designed to test the heat sinks with different configurations. Temperature data were collected at different locations by a Data Acquisition (DAQ) system and recorded by Labview software to investigate the heat transfer characteristics of the heat sink. Three heat sinks, with different configurations, were tested. They all included microchannels of width 50 μm, depth 60 μm, and fin width 200 μm. Some Typical results on heat transfer are presented, along with discussion on the efficiency for heat removal.

The Application of Heat Pipe Heat Sink for High Power LED Lamps

2014 ◽  
Vol 602-605 ◽  
pp. 2713-2716 ◽  
Author(s):  
Xin Rui Ding ◽  
Yu Ji Li ◽  
Zong Tao Li ◽  
Yong Tang ◽  
Bin Hai Yu ◽  
...  
Keyword(s):  
Heat Pipe ◽  
Thermal Performance ◽  
High Power ◽  
Heat Sink ◽  
Heat Dissipation ◽  
Heat Sinks ◽  
Practical Significance ◽  
Heat Accumulation ◽  
Element Analysis ◽  
High Power Led

LED has been regarded as the next generation lighting source. As for high power LED lamps, heat accumulation will cause a series of problems. Therefore, thermal management is very important for designing a high power LED lamp. Three types of heat sinks are designed by using the finite element analysis (FEA) method for an 180W high power LED lamp. Then the optimized heat sinks are developed and experiments are performed to demonstrate the simulated results. At the same time, the thermal performances with different working angles are investigated experimentally. The heat sink with heat pipe has a better heat dissipation performance than the conventional heat sink under the same input power. The working angles of the lamps greatly influence the thermal performance of each heat sink. For the same heat sink, the temperature varies with different install directions and working angles. Finally, the heat sink with the best thermal performance is recommended. The results have practical significance in designing high power LED lamps.

scholarly journals Experimental analysis of effect of base with different inner geometries filled nano PCM for the thermal performance of the plate fin heat sink

2021 ◽  
pp. 243-243
Author(s):  
Periyannan Lakshmanan ◽  
Saravanan Periyasamy ◽  
Mohan Raman
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Reynolds Number ◽  
Phase Shift ◽  
Experimental Research ◽  
Thermal Performance ◽  
Heat Sink ◽  
Electronic Devices ◽  
Base Plate ◽  
Heat Sinks

Experimental research demonstrates the performance of electronic devices on plate fin heat sinks in order to guarantee that operating temperatures are kept as low as possible for reliability. Paraffin wax (PCM) is a substance that is used to store energy and the aluminum plate fin cavity base is chosen as a Thermal Conductivity Enhancer (TCEs). The effects of PCM material (Phase shift material), cavity form base (Rectangular, Triangular, Concave and Convex) with PCM, Reynolds number (Re= 4000-20000) on heat transfer effectiveness of plate fin heat sinks were experimentally explored in this research. The thermal performance of concave base plate fin heat sink with PCM is increased up to 7.8% compared to other cavity base heat sinks.

Effect of Flow Bypass on the Performance of Longitudinal Fin Heat Sinks

1994 ◽  
Vol 116 (3) ◽  
pp. 206-211 ◽  
Author(s):  
R. A. Wirtz ◽  
Weiming Chen ◽  
Ronghua Zhou
Keyword(s):  
Heat Transfer ◽  
Forced Convection ◽  
Thermal Performance ◽  
Heat Sink ◽  
Design Guidelines ◽  
Heat Sinks ◽  
Air Cooling ◽  
Regular Array ◽  
Electronic Package ◽  
And Performance

Heat transfer experiments are reported on the thermal performance of longitudinal fin heat sinks attached to an electronic package which is part of a regular array of packages undergoing forced convection air cooling. The effect of coolant bypass on the performance of the heat sink is assessed and performance correlations for reduced heat transfer due to this effect are developed. These correlations are used to develop design guidelines for optimal performance.

Effect of channel and fin geometries on a trapeze plate-fin heat sink performance

2021 ◽  
pp. 095440892110059
Author(s):  
Özgür Özdilli ◽  
Seyfi Şevik
Keyword(s):  
Heat Transfer ◽  
Thermal Performance ◽  
Heat Sink ◽  
Channel Model ◽  
Rectangular Channel ◽  
Heat Sinks ◽  
Junction Temperature ◽  
Base Temperature ◽  
Thermal Enhancement ◽  
Standard Plate

This study aims to achieve a minimum base temperature (or junction temperature) and hence better thermal performance. Trapezoidal curved plate-fin heat sink with dolphin fins and rectangular channel (Model-1) and trapezoidal curved plate-fin heat sink with dolphin fins, cut corner, and rectangular channel (Model-2) were designed and compared with a standard plate-fin heat sink. The effects of fins on the airflow and heat transfer in designed plate-fin heat sinks have been investigated numerically. The numeric results show that the use of fins and small changes in geometry significantly improve the heat transfer rate. Outcomes of the study showed 44–51% and 57–62% convective heat transfer enhancement compared with a standard plate-fin heat sink, without any overall mass augmentation, in Model-1 and Model-2, respectively. The presence of dolphin fins reduces the thermal resistance by up to 30%, which contributes to the overall thermal enhancement of the designed plate-fin heat sinks. Simulation results show that increasing the fins in areas close to the heat source and reducing the non-working areas significantly influence the thermal performance of heat sinks. The results also show that the trapeze plate-fin heat sinks with the different channel-fin geometries are superior to the standard trapeze plate-fin heat sink in thermal performance.

Convective Heat Transfer Measurements of Die-Casting Heat Sinks

2009 ◽  
Vol 419-420 ◽  
pp. 345-348
Author(s):  
Rong Yuan Jou
Keyword(s):  
Free Convection ◽  
Forced Convection ◽  
Thermal Performance ◽  
Temperature Difference ◽  
High Power ◽  
Heat Sink ◽  
Die Casting ◽  
Heating Power ◽  
Heat Sinks ◽  
Plate Temperature

For applications of high-power LED illumination and advanced CPU electronic cooling, since the traditional plate heat sinks by aluminum extrusion are simple geometry only and with limited thermal performance, a new design and new fabrication process of heat sink for high-density heat flux applications is inevitable. In this study, a heat sink fabricated by vacuum die-casting is analyzed. To evaluate the thermal performance of this heat sink, two experiments, free convection measurements in an enclosure and forced convection measurements in a wind tunnel, are conducted by two experimental methods of thermocouples and IR thermograph. As to free convection experiments, compared to the free convection over a plate, temperature decrement by the attached casting of pin-fin heat sink is 46.2% for the input power of 10W. In the case of 15W heating power, temperature distribution along center pin shows uniformly distributed temperature along length direction, but there is a temperature difference of 9.5°C,varied from 86.9°C to 77.4°C, at outer pin. As to the case of 10W heating power, there is a temperature difference of 6.5°C, varied from 69.2.9°C to 62.6°C, at the outer pin. Furthermore, forced convection experiments show that resistances of heat-sink casting are decreased when Reynolds numbers are increased, and a linear relationship between pressure drop and Reynolds number is noticed. Base on the measurement results, this heat sink casting can be a feasible thermal solution of LED and high-power chip products.

Numerical Modeling of Buoyancy Induced Convection in Finned Heat Sinks in Presence of Unheated and Heated Shrouds

2005 ◽  
Author(s):  
S. S. Bahga ◽  
A. Bhattacharya ◽  
Roop L. Mahajan
Keyword(s):  
Heat Transfer ◽  
Thermal Performance ◽  
Heat Sink ◽  
Numerical Study ◽  
Numerical Results ◽  
Heat Sinks ◽  
Maximum Heat ◽  
Maximum Heat Transfer ◽  
Wide Range ◽  
The Impact

This paper investigates the effects of the presence of unheated and heated shrouds on the thermal performance of longitudinal finned heat sinks. A comprehensive numerical study was conducted to determine the impact of the shroud clearance from the tip of the fins and shroud heating. The first part of the study deals with the effects of an unheated shroud on finned heat sinks of different fin height, fin pitch and length in an attempt to cover a wide range of geometry. The numerical results reveal an optimum clearance for maximum heat transfer. For all heat sinks studied the unheated shroud improved the performance by as much as 15% until the shroud was very close when the performance decreased by as much as 10%. In the second part of the paper, the effects of heating of the shroud were considered. In these numerical runs, an isothermal boundary condition was imposed on the shroud. For the heating levels considered, it was found that heating of the shrouds can increase or lower the thermal performance of the heat sink depending on the heat sink geometry and shroud clearance. Finally, the numerical results also revealed a systematic dependence of the normalized Nusselt number on the Rayleigh number for a given heat sink geometry.

Thermal Performance of Triangular Folded Fin Heat Sinks in a Duct

2003 ◽  
Author(s):  
Seo Young Kim ◽  
Taeho Ji ◽  
Dong Gyu Choi ◽  
Byung Ha Kang
Keyword(s):  
Heat Transfer ◽  
Thermal Resistance ◽  
Flow Velocity ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Thermal Performance ◽  
Heat Sink ◽  
Base Plate ◽  
Heat Sinks ◽  
Heat Transfer Characteristics

Experiments have been carried out to investigate the convective heat transfer characteristics from triangular folded fin heat sinks in a suction-type fan duct. The dimension of the triangular folded fin heat sinks is 62 mm in height with a 12 mm thick base plate, 292 mm in width, and 447 mm in length. The inlet flow velocity is varied in the range of 0.6–5.3 m/s. Thermal performance of triangular folded fin heat sinks is evaluated in terms of thermal resistance of heat sinks according to flow velocity and fan power. The results obtained show that the present triangular folded-fin heat sink shows a higher thermal performance compared to a conventional extruded plate-fin heat sink. Especially, a perforated slit folded-fin heat sink displays a lower thermal resistance. As the number of slit fabricated on the perforated folded fins increases, thermal performance is more pronounced.

Sign in / Sign up

Export Citation Format

Share Document