A Study of an Effective Heat-Dissipating Piezoelectric Fan for High Heat Density Devices

Abstract

Abstract:Heat dissipation per unit volume has grown rapidly, as the size of modern electronic devices has continued to decrease. The air flow induced by an oscillating cantilever blade enhances the heat transfer performance of high heat density devices. The heat transfer improvement mainly depends on the velocity magnitude and distribution of air streams induced by the vibrating blade. Accordingly, this study numerically and experimentally examines the time-varying flow characteristics of a vibrating cantilever for five blade types. The blades are rectangular or trapezoidal with various widths and actuated at various frequencies. The fluid domain is numerically discretized using a dynamic meshing scheme to model the three-dimensional time-varying vibrating blade. The experiment utilizes nine hot-wire velocity meters to measure the average velocities. The flow structure with streamlines and velocity contours of the induced air flow are determined at various section planes. The results show that a major maximum-velocity region appears around the blade tip and that four minor local-maximum-velocity regions appear at the four corners. In addition, the width and width ratio of the blade significantly affects the velocity distribution of the flow induced by the vibrating cantilever blade.

Recent Developments in Air Pumps for Thermal Management of Electronics

“…Lin et al [42] and Li et al [43] performed similar experiments and simulations to show how the beam shape affects the Fig. 9 The schematic of the turboblower [32] Fig.…”

Numerical and Experimental Study on the Heat Dissipation Performance of a Novel System

“…where qhb, qs, qc, and qr are calculated using Equations (5)- (8), respectively. qhb is the heat flux from the microheat pipe to the radiative plate, qs is the absorbed atmospheric radiation from the aerosphere to the radiative plate, qc is the convective heat flux from the radiative plate to the ambient air, and qr is the radiant heat flux from the radiative plate to the outer environment.…”

“…Therefore, heat dissipation technology has become the key to achieving long-life and high-reliability performance [5]. For this purpose, many effective methods have been implemented in forced convection cooling techniques, such as heat sinks cooled by air or liquid [6][7][8], microchannel pipes [9], and new materials and new technology [10][11][12]. However, the conventional air-cooled cooling systems are often inadequate to remove excessive heat from electronic components because of narrow heat dissipation space [13].…”

A review of piezoelectric fans for low energy cooling of power electronics

“…Equation 4 assumes uniform blade width and thickness along its length, and as such the mass of the blade acts as a uniformly distributed load during forced vibration [42]. Lin et al [28] consider the geometries summarised in Figure 4 and Table 2. Fan E is found to have the highest resonant frequency, and Fan D the lowest.…”

“…In research, blade thickness is the most commonly used variable to adjust the resonant frequency of a blade, allowing for investigation across a range of frequencies. Unlike length, which would also alter frequency, the thickness of the blade has a negligable impact on the imparted air flow field [28].…”