Experimental study of heat transfer and pressure drop in micro-channel based heat sinks with tip clearance

► We study experimentally the effect of tip clearance height on in micro channel based heat sinks. ► The effects that are studied are heat transfer and pressure drop. ► We find that tip clearance reduces heat transfer slightly and pressure drop significantly. ► The effect becomes more important at lower Reynolds numbers. ► The findings can be used to optimize thermal control systems in engineering applications.