Experimental investigations of flow boiling heat transfer and pressure drop in straight and expanding microchannels - A comparative study

► Flow boiling experiments conducted in straight and expanding microchannels. ► Their two-phase heat transfer and pressure drop performance compared. ► Pressure drop in expanding microchannels is significantly lower. ► Expanding microchannels have better stabilizing effect. ► At medium/higher heat fluxes expanding microchannels have lower wall temperature.