Enhanced thermal performance with high-amplitude intermittent impingement cooling

The advances of many future engineering applications rely on effective cooling techniques. Beyond the traditional thermal management solutions, the design potential of unsteady impingement cooling is still under-explored. As a combined experimental and numerical study, this paper reports new findings on high-amplitude intermittent impingement cooling with controlled unsteady patterns. Specifical attention was paid on the intermittent flow close time ratio. The experimental work involved unsteady cooling performance measurement with a small-scale water tunnel system. Unsteady Reynolds Averaged NavierStokes Simulation (URANS) was conducted to illustrate the unsteady flow physics, and to evaluate the cooling performance at a wider range of flow conditions (average Reynolds number 2800 < Re-m < 10,000, pulsating frequency 0.1 Hz < f < 2 Hz, close time ratio 0.2 < gamma < 0.8). Both experimental and numerical data confirm a remarkable improvement of overall cooling efficiency by high-amplitude intermittent impingement flow. Especially around the wall jet region, the enhancement can reach as high as 50%. The generation and interaction of vortex rings break the development of thermal boundary layer, and enhance the generation of near wall turbulence, especially for the wall jet region. Saving in coolant consumption with high-amplitude intermittent impingement cooling technique in practice is also demonstrated. The novel concept presented in this paper can be applied to a wide range of applications including electronic cooling, deicing, gas turbine blade cooling, etc. (c) 2021 Elsevier Ltd. All rights reserved.

Automated summary

This paper presents a combined experimental and numerical study on high-amplitude intermittent impingement cooling. The results show a remarkable improvement in overall cooling efficiency, especially in the wall jet region.