Characteristic Study on the Optimization of Pin-Fin Micro Heat Sink

Abstract

The need for dissipating heat from microsystems has increased drastically in the last decade. Several methods of heat dissipation using air and liquids have been proposed by many studies, and pin-fin micro heat sinks are one among them. Researchers have developed several effective pin-fin structures for use in heat sinks, but not much effort has been taken towards the optimization of profile and dimensions of the pin-fin. In this paper the authors studied the effect of different pin-fin shapes on the thermal resistance and pressure drop in a specific micro heat-sink. Optimization subjected to two different constraints is studied in this paper. The first optimization is subjected to constant flow rate and the second one is subjected to constant pressure drop. Both optimization processes are carried out using computer simulations generated using COVENTORWARE™. Two of the best structures from each of these optimization studies are selected and further analysis is performed for optimizing their structure dimensions such as width, height and length. A section of the total micro heat-sink is modeled for the initial optimization of the pin-fin shape. The model consists of two sections, the substrate and the fluid. Six different shapes: square, circle, rectangle, triangle, oval and rhombus were analyzed in the initial optimization study. Preliminary tests were conducted using the first model described above for a flow rate of 0.6ml/min. The non dimensional overall thermal resistance of the heat sink, and the nondimensional pumping power was calculated from the results. A figure of merit (FOM) was developed using the nondimensional thermal resistance and nondimensional pumping power for each structure with different pin-fin shapes. Smaller the value of FOM better the performance of the heat sink. The study revealed that the circle and ellipse structures have the best performance and the rectangle structure had the worst performance at low flow rates. At high flow rates rectangular and square structures have the best performance.

Parametric study on the combined thermal and hydraulic performance of single phase micro pin-fin heat sinks part I: Square and circle geometries

“…A few groups have tried to focus their work on the pressure drop across the device along with the reduction in the thermal resistance. This paper builds upon the study carried out earlier by John et al [11] and extends it to consider the effects of pin-fin aspect ratio, hydraulic diameter, and pitch distance in the axial and transverse flow directions. The present study focuses on understanding these effects for two shapes of pin-fins: 1) circle and 2) square.…”

“…John et al [11] investigated the effect of the micro pin-fin geometries on the performance of the micro pin-fin heat sinks in 2009. Six different geometries were studied under two different constraints; constant liquid flow rate (1e5 ml/h) and constant pressure drop (50 e100 kPa).…”

Optimization of micro pin-fin heat sink with staggered arrangement

“…The pin efficiency of the pin-fin heat sinks is low at micro level and this issue can be resolved by using shorter pin-fins [5]. At very low, intermediate and high flow rates circular, ellipse, and rectangle pin-fins were the best performers [8]. The thermal resistance is the dominating factor at lower and intermediate flow rates and pumping pressure is the dominating factor at intermediate and high flow rates.…”

A Kind of Microchannel Heat Sink Optimization for High Power Chips Based on CFD and Non-Silicon MEMS Technology

“…Firstly the structures of the heat sinks are designed and optimized, for example, LUO et al [3] studied a honeycomb microchannel cooling system which with the characters of low-density combine a certain stiffness, strength, crushing energy absorption. John et al [4] focused on the different shapes of pin-fins to enhance the efficiency of the heat sink. In their paper six different shapes of pin-fins are arranged in a heat sink and was compared to the heat sink that without any pin-fin structures and made a weighted average method to determine a figure of merit for performance of each shape of pin-fin structure.…”