Natural and forced convection heat transfer coefficients of various finned heat sinks for miniature electronic systems (original) (raw)

ENHANCEMENT OF HEAT TRANSFER FROM PLATE FIN HEAT SINKS

Heat Sinks are an extremely useful component used to lower the maximum temperature of various electronic devices during operation so as to increase their thermal efficiency and performance. Fins constitute an important and integral component of sinks. It is a passive cooling technique. Plate fin heat sinks are used in varied applications owing to its low manufacturing cost, ease of manufacture and its economical way to dissipate unwanted heat. Steady state natural convection is experimentally investigated for 03 sets of vertically mounted fin heat sinks. Aluminum is used because of its high conductivity. Length and fin thickness is kept constant at 200 mm and 05 mm respectively. Fin height is successively increased as 10mm, 30mm, 50mm.Aspect Ratio for above three sets is thus 0.05, 0.15 and 0.25 respectively. Effect of varying height, heat input and aspect ratio, keeping length constant is investigated on heat transfer through the sinks.

Numerical Investigation of Convective Heat Transfer in Pin Fin Type Heat Sink used for Led Application by using CFD

An analysis of the effect of orientation on the heat transfer in a scaled model pin fin heat sink utilized in Light Emitting Diode (LED) lighting has been carried out using numerical method. The present study involves natural convective heat transfer that takes place in particular heat sink. A pin fin type heat sink has been studied since they are widely used in LED lighting systems which in turn are facing a lot of thermal challenges when they are integrated with high power lighting system. The numerical study is carried out using ANSYS FLUENT software package. The modeling and meshing has been generated using ANSYS GAMBIT v.2.3.16 module which one later imported into ANSYS FLUENT v.6.3.26 module for analysis. In order to carry out a detailed analysis various parametric studies are conducted for different LED power wattages such as 10 W considering different orientations obtained by changing the angles from 0° to 45° has been carried out. From the results it can be concluded that the dissipation of heat in the heat sink is dependent on the orientation of the heat sink. The particular study will be useful to optimize the heat sink used in the LED lighting system.

Enhancement of Natural Convection Heat Transfer from Horizontal Rectangular FIN Arrays : A Review

In this study, various fin geometries are referred for steady-state natural convection heat transfer. The effects of fin spacing, fin length, fin height, % of perforations, shape of perforations etc. are studied. For high powered street LED lights heat sinks with horizontal fin arrays are utilized. Large amount of heat generated in these street LED " s must have to be dissipated effectively, so that the life span of the same can be enhanced. For the heat sinks currently utilized in the high powered street LED " s a stagnation zone is formed at the symmetry centre of the fins this causes the problem in air circulation ultimately affects the heat dissipation capacity of the heat sink. Therefore there should be the proper provision for air to be drawn.

Heat transfer enhancement in a p-shape finned radial heat sink subjected to natural convection: Thermal significance of slot and dimples in fin

ITEGAM

This study presents the optimum design of the radial heat sink for light-emitting diode (LED) under natural convection. A radial heat sink with a hollow circular base and a P-shape fin type incorporated with either slots or both slots and dimples was numerically investigated using the ANSYS (Fluent) commercial code, with the aim of achieving better cooling performance at a lower heat sink mass. The average temperature () and mass of the HS for various model designs, namely; Type A (HS with plain fin), Type B (HS with slot) and Type C (HS with both dimples and slot) were compared to select the best configuration. The effect of heat flux (700 ≤̇≤ 1900) on average temperature of radial heat sink was investigated. It was found that for all three models, the temperature difference between the HS and the ambient air of the fluid domain linearly increased with heat flux. At ̇= 1900 / 2 , when compared to Type A (HS with plain fins), Type C (HS with slot and dimples) models offered the best cooling performance, followed by Type B where the mass and average temperature of the heat sink is reduced by 13.7% and 5.1%, 8.3% and 1%, respectively.

Thermal Analysis of Vertical Plate Fin Heat Sink

E3S Web of Conferences, 2020

Heat Sinks are widely used to remove the heat from the components which are generating heat during their functioning. Overheating causes malfunctioning of the components as well as it is responsible for reducing their life. Free convection is very common way of heat transfer from the heat sink considering power requirement, pressure drop and cost of the forced convection. This paper presents the thermal analysis of vertical plate fin heat sink by theoretical and experimental method at variable heat input. The results are obtained by taking experimental observations and are validated with already existing correlations suggested by various researchers in the literature.

REVIEW OF NATURAL CONVECTIVE HEAT TRANSFER FROM RECTANGULAR VERTICAL PLATE FINS

In many engineering applications heat transfer rate is important factor. From many years efforts have been taken to develop heat transfer enhancement techniques for improving performance of equipments. Enhancement of heat transfer takes place by active method and passive method. Among passive method Fins are widely use to enhance heat transfer rate. Fins are use in a wide variety of engineering applications of passive cooling of electronic equipment such as compact power supplies, portable computers and telecommunications enclosures. In this paper, convection heat transfer through rectangular fins is reviewed. Many researchers studied convective heat transfer through rectangular fins and fin arrays. Various experimental studies have been made to investigate effect of fin height, fin spacing, fin length and fin thickness over convective heat transfer. Experimental and numerical studies are done in natural, mixed and forced convection. Some investigators found sets of correlations to give relation between various parameters of heat sink.

MODELING AND THERMAL ANALYSIS OF HEAT SINK WITH SCALES ON FINS COOLED BY NATURAL CONVECTION

Heat removal is often a significant endeavor in LED luminaries. A lower junction temperature of LED impacts efficiency, life, performance & reliability. This work addresses thermal performance of few popular designing approaches on Fins of heat sink and it's correlation with junction temperature (also referred as soldering point temperature) of LEDs cooled by natural convection. A comparative thermal simulation results has been presented on basic rectangular fins, pin fins and trapezoidal scaled tapered fins using SolidWorks Thermal Simulation. It is observed that thermal mass, exposed surface area & geometric placement of fins plays a key role in deciding performance of fins and Heat Sink. A high power LED array is used as uniform heat load of 65 watt. An optimized heat sink has typical functional dependencies on material, fin structure, ambient temperature of surrounding fluid, orientation with respect to gravity, color, texture and conductivity of interface layer used between LED and heat sink.

Natural convection heat transfer enhancement in new designs of plate-fin based heat sinks

Experimental investigation was conducted to measure the convective heat transfer coefficient and thermal performance of plate fins and plate cubic pin-fins heat sinks, under natural convection regime. The investigation was conducted for Rayleigh number from 8×10 6 to 9.5×10 6 and input heat of 10 W to 120 W. The fin spacing and fin numbers are varied between 5-12 mm and 5-9, respectively. The results demonstrated that plate cubic pin-fins heat sinks have lower thermal resistance and higher heat transfer, compared to plate fins heat sinks. Heat transfer enhancement of new-designed heat sinks is about 10% to 41.6% higher, compared to normal pin-fins. Increasing fin spaces in all types of studied heat sinks cause lower thermal resistance. But, increasing fin numbers does not cause better heat transfer. The best heat sink design was a plate cubic pin-fin heat sink with 7 fins and 8.5 mm fin spacing. Finally, empirical equations have been developed to correlate the average Nusselt number as

EXPERIMENTAL INVESTIGATION OF PLANTED PIN FIN IN PLATE FIN HEAT SINK FOR ELECTRONICS COOLING

and phrases: plate-ellipse pin fin heat sink, forced cooling of electronic devices, computational fluid dynamics. Abstract In the present study, the thermal performance of plate-ellipse, plate-circular pin fin heat sink is carried out experimentally and physical impending into the flow and heat transfer characteristics is provided. The performance of heat sink is examined for different Reynolds number, fin thickness, copper and CCC base plates. The plate-circular pin fin heat sink is composed of a plate fin heat sink and some circular pins between plate fins. The purpose of this study is to examine the effects of the configurations of the elliptical, circular pin fins design. In this paper, the thermal performance of plate-circular pin fin heat