Water jet impingement boiling from structured-porous surfaces

Structured-porous surfaces were created by diffusion bonding a single layer or multiple layers of highly conductive copper wire mesh screen onto plain heat transfer base surfaces. Flow boiling heat transfer experiments were then conducted with a liquid water jet impinging onto those porous copper surfaces under atmospheric pressure. For comparison, experiments of jet impinging on a plain copper surface were also conducted. The effect of jet Reynolds number, jet inlet subcooling, and porous layer thickness on boiling heat transfer were explored. Surface ageing and data repeatability were also discussed. The results show that a base surface heat flux of 674 W/cm(2) was reached at a superheat of 5 K and a jet Reynolds number of 10,000 with a four-layer 200-mesh test surface. Compared to jet impinging on a plain copper surface under identical working conditions, a fourfold performance enhancement was obtained in increasing heat transfer from the base surface. (C) 2013 Elsevier Ltd. All rights reserved.