Experimental investigation of local flow boiling heat transfer and pressure drop characteristics in microgap channel

► Experiments are performed at three microgap heat sinks which meet vapor confinement. ► Lower the microgap depth, better the performance is achieved. ► Higher local heat transfer coefficient is achieved at lower mass flux. ► Effect of heat flux on pressure drop increases as microgap dimension decreases. ► Smaller microgap maintains uniform wall temperature and lower temp fluctuation.