Performance Analysis, Optimum and Verification for Parallel Plate Heat Sink Associated With Single Non-Uniform Heat Source

2003 ◽  
Author(s):  
Vincent Lin ◽  
Sih-Li Chen
Keyword(s):  
Heat Source ◽  
Thermal Resistance ◽  
Heat Sink ◽  
Parallel Plate ◽  
Source Area ◽  
Plate Heat ◽  
Uniform Heat ◽  
Source To Sink ◽  
Good Agreement

This paper develops an analytical model to predict the overall thermal resistance of a parallel plate heat sink associated with a non-uniform heat source. Using constrictive ratio and apparent interface ratio to interpret equivalent heat source area and maximal heat flux on source-to-sink contacting surface, the non-uniform heat source problem can be simplified as an equivalent uniform heat source problem. Then by using the existed correlations the present model can calculate the overall thermal resistance as a function of heat sink geometry, properties, interface conditions, and airflow velocity. An experimental investigation is performed to verify the theoretical model. Prediction results show good agreement with experimental measurements over a number of testing units. A case study of optimum is also proposed to demonstrate and understand the effects of variable constrictive ratio and apparent interface resistance.

scholarly journals Integration of a Pulsating Heat Pipe in a Flat Plate Heat Sink

2014 ◽  
Author(s):  
Mitchell P. Hoesing ◽  
Gregory J. Michna
Keyword(s):  
Thermal Resistance ◽  
Flat Plate ◽  
Heat Pipe ◽  
Heat Sink ◽  
New Technologies ◽  
Operating Conditions ◽  
Working Fluid ◽  
High Heat Flux ◽  
Pulsating Heat Pipe ◽  
Plate Heat

The ongoing development of faster and smaller electronic components has led to a need for new technologies to effectively dissipate waste thermal energy. The pulsating heat pipe (PHP) shows potential to meet this need, due to its high heat flux capacity, simplicity, and low cost. A 20-turn flat plate PHP was integrated into an aluminum flat plate heat sink with a simulated electronic load. The PHP heat sink used water as the working fluid and had 20 parallel channels with dimensions 2 mm × 2 mm × 119 mm. Experiments were run under various operating conditions, and thermal resistance of the PHP was calculated. The performance enhancement provided by the PHP was assessed by comparing the thermal resistance of the heat sink with no working fluid to that of it charged with water. Uncharged, the PHP was found to have a resistance of 1.97 K/W. Charged to a fill ratio of approximately 75% and oriented vertically, the PHP achieved a resistance of .49 K/W and .53 K/W when the condenser temperature was set to 20°C and 30°C, respectively. When the PHP was tilted to 45° above horizontal the PHP had a resistance of .76 K/W and .59 K/W when the condenser was set 20°C and 30°C, respectively. The PHP greatly improves the heat transfer properties of the heat sink compared to the aluminum plate alone. Additional considerations regarding flat plate PHP design are also presented.

Optimization of a Parallel Plate Heat Sink Using Volume Averaging Theory

2005 ◽  
Author(s):  
Benjamin A. Blake ◽  
Ivan Catton
Keyword(s):  
Heat Sink ◽  
Parallel Plate ◽  
Volume Averaging ◽  
Maximum Heat ◽  
Plate Heat ◽  
Maximum Heat Transfer ◽  
Average Theory ◽  
Fin Thickness ◽  
Nusselt Number Correlation ◽  
Fin Length

A parallel plate heat sink is optimized using a model based on the volume average theory (VAT). VAT is briefly developed and the numerical scheme is described. The numerical simulation is carried out in FORTRAN. The resulting VAT solutions are verified by comparison to experimental results via a Nusselt number correlation. The procedure for optimization is described and, as an example, a heat sink of a size appropriate for cooling a CPU is optimized for minimum thermal resistance, maximum effectiveness, and maximum heat transfer rate per unit volume. Seven parameters are included in the simulations: fin thickness, fin length, fin height, fin pitch to thickness ratio, base width, base thickness, and pore Reynold’s number. Three are chosen for optimization: fin height, fin pitch, and pore Reynolds number. The responses are optimized for an aluminum heat sink.

scholarly journals Improving thermal performance of micro-channel electronic heat sink using supercritical CO2 as coolant

2019 ◽  
Vol 23 (1) ◽  
pp. 243-253 ◽  
Author(s):  
Jahar Sarkar
Keyword(s):  
Heat Source ◽  
Thermal Resistance ◽  
Heat Sink ◽  
Supercritical Co2 ◽  
Heat Transfer Fluid ◽  
Inlet Temperature ◽  
Sharp Change ◽  
Micro Channel ◽  
Pumping Power ◽  
Flux Flow

In view of increasing tendency of power density of electronic systems, cooling performance improvement of micro-channel heat sink is an emerging issue. In the present article, supercritical CO2 is proposed as a heat transfer fluid in micro-channel heat sink for power electronics cooling. Energetic and exergetic performance analyses of micro-channel heat sink using supercritical CO2 have been done and compared with conventional coolant, water. To take care of sharp change in properties in near critical region, the discretization technique has been used for simulation. Effects of both operating and geometric parameters (heat flux, flow rate, fluid inlet temperature, channel width ratio, and channel numbers) on thermal resistance, heat source (chip) temperature, pressure drop, pumping power and entropy generation are presented. Study shows that the thermal resistance, heat source temperature and pumping power are highly dependent on CO2 inlet pressure and temperature. Supercritical CO2 yields better performance than water for certain range of fluid inlet temperature. For the studied ranges, maximum reduction of thermal resistance by using CO2 is evaluated as 30%. Present study reveals that there is an opportunity to use supercritical CO2 as coolant for power electronic cooling at lower ambient temperature.

Experiments on the Flow and Heat Transfer in Fine Pitch Parallel Plate Heat Sinks With Top Inlet Side Exit Flow

2007 ◽  
Author(s):  
Felipe E. Ortega-Gutierrez ◽  
Alfonso Ortega
Keyword(s):  
Thermal Resistance ◽  
Heat Sink ◽  
Parallel Plate ◽  
Ad Hoc ◽  
Loss Coefficient ◽  
Heat Sinks ◽  
Pressure Measurements ◽  
Total Thermal Resistance ◽  
Fine Pitch ◽  
Jet Nozzle

Detailed temperature and pressure measurements in high aspect ratio parallel plate fin heat sinks were made in a Top Inlet Side Exit (TISE) experiment configuration without top bypass flow. Air flow was supplied to the top of the heat sink using a rectangular jet nozzle with three different jet nozzle widths, Wj. The study covered five jet velocities and three different jet nozzle width to heat sink length ratios. Static pressure measurements were made along the spanwise centerline inside the heat sink and on the mounting plate outside the heat sink. The measurements were used to study the influence of the jet impinging on the top of the heat sink on the loss coefficient of the heat sink. It was found that the overall loss coefficient was dependent on Re, Wj, the fin spacing, b, and the jet nozzle width relative to the heat sink length, Wj/L. Temperature measurements were made to study the total thermal resistance with no base heat spreading. An ad hoc model was used to predict the total thermal resistance of the heat sink in this complicated flow. The model modifies the total cooled area of the fin as a function of jet width and heat sink geometry. Good agreement was found with the experimental data for the cases of Wj/L = 1.0 and 0.5. The model does not work well in the case of Wj/L = 0.25.

Energy Payback Optimization of Thermoelectric Power Generator Systems

2010 ◽  
Author(s):  
Kazuaki Yazawa ◽  
Ali Shakouri
Keyword(s):  
Power Generation ◽  
Heat Source ◽  
Thermal Resistance ◽  
Thermoelectric Power ◽  
Output Power ◽  
Heat Sink ◽  
Generation System ◽  
Thermoelectric Power Generation ◽  
Energy Payback ◽  
Power Generation System

An analytic model for optimizing thermoelectric power generation system is developed and utilized for parametric studies. This model takes into account the external thermal resistances with hot and cold reservoirs. In addition, the spreading thermal resistance in the module substrates is considered to find the impact of designing small fraction of thermo elements per unit area. Previous studies are expanded by a full optimization of the electrical and thermal circuits. The optimum condition satisfies both electrical load resistance match with the internal resistance and the thermal resistance match with the heat source and the heat sink. Thermoelectric element aspect ratio and fill factor are found to be key parameters to optimize. The optimum leg length and the maximum output power are determined by a simple formula. The output power density per mass of the thermoelectric material has a peak when thermo elements cover a fractional area of ∼1%. The role of the substrate heat spreading for thermoelectric power generation is equally significant as thermoelement. For a given heat source, the co-optimization of the heat sink and the thermoelectric module should be performed. Active cooling and the design of the heat sink are customized to find the energy payback for the power generation system. The model includes both the air cooled heat sinks and the water cooled micro channels. We find that one can reduce the mass of thermoelement to around 3∼10% of that in commercial modules for the same output power, as long as the module and elements are designed properly. Also one notes that higher heat flux sources have significantly larger energy payback and reduced cost per output power.

Heat Sink Matching for Thermoelectric Generator

2011 ◽  
Vol 383-390 ◽  
pp. 6122-6127 ◽  
Author(s):  
Ze Guang Zhou ◽  
Dong Sheng Zhu ◽  
Yin Sheng Huang ◽  
Chan Wang
Keyword(s):  
Numerical Calculation ◽  
Heat Source ◽  
Thermal Resistance ◽  
Output Power ◽  
Analytical Model ◽  
Temperature Difference ◽  
Heat Sink ◽  
Thermoelectric Generator ◽  
Thermoelectric Module

Heat sink does affect on the performance of thermoelectirc generator according to the studies of many authors. In this paper, an analytical model inculding the number of thermocouples and the thermal resistance of heat sink is derived. The match between the thermoelectric module and heat sink is discussed by numerical calculation also. The results show that the thermal resistance of thermoelectric module should be designed to match that of heat sink in order to get the highest output power for a given heat sink. But for a given thermoelectric module, the output power increases with the decrease of heat sink thermal resistance, and there is a suitable heat sink due to the limit of the temperature difference between the heat source and coolant.

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