Application of a Valveless Impedance Pump in a Liquid Cooling System

Abstract

In this study, a novel valveless impedance pump is applied, for the first time, in the thermal management of high performance electronic systems. This small pump comprises an amber latex rubber tube, connected at both ends to rigid copper tubes of different acoustic impedance, and a simple, economic, quiet and energy-efficient actuation mechanism, which combines a small DC motor and a cam. The motor activated cam periodically compresses the elastic tube at a position asymmetric from the tube ends.Traveling waves, emitted from the compression, combine with reflected waves, at the impedance-mismatched positions (rubber tube/copper tube interfaces). The resulting wave interference creates a pressure gradient, with the potential to generate a net flow. Several experimental set-ups for performance tests, using a single impedance pump, open system, with isothermal flow, and a closed liquid cooling system were designed and implemented.The performance of the impedance pump was affected significantly by the actuation This is the Pre-Published Version.

Design and Analysis of a Valveless Impedance Pump for a Direct Sodium Borohydride–Hydrogen Peroxide Fuel Cell

“…Valveless Impedance Pump. The impedance pump design of Wen et al [16] was modified and further extended. As shown in Fig.…”

“…The stainless-steel tubes had a 0.5-mm wall thickness and an outer diameter of 5.0 mm. According to the earlier experimental studies of Wen et al [16], actuating at x/L = 1/8 (see Fig. 1) and Δy/D = 1 (i.e., complete closure of the elastic tube) yields the maximum flowrate at any compression frequency f. A small direct control (DC) motor (FM-2088, Tricore Corp., Taiwan) was used to drive a cam and to compress the rubber tube at x/L = 1/8 and Δy/D = 1 at various f. The cam was made of lead solder because of its good lubrication characteristics under dry contact; its detailed dimensions are shown in the upperright inset in Fig.…”

“…In the past two decades, a novel valveless scheme based on the impedance mismatch effect has been introduced in engineering applications [12][13][14][15][16]. This valveless impedance pump has a simpler structure and can generate a higher flowrate than the peristaltic schemes.…”

“…1, the valveless impedance pump typically consists of a flexible section connected at both ends to rigid sections of different acoustic impedance. The flexible section is compressed periodically at a location asymmetrical from the ends with various actuation mechanisms, including electric motors [12,16], electromagnetic actuators [13][14][15][17][18][19][20][21], and piezoelectric (PZT) actuators [22]. A pair of pressure waves is emitted in opposite directions each time the tube is compressed.…”

Computational study of a novel valveless design of a macroscale piston pump

“…The generation of fluid motion is secured by the so-called Liebau effect, when the less rigid tube is periodically pressed. This principle of pumping can be used for both open and closed loops and also for macro and micro scale pumping [9,10,16].…”