Effects of electric field on flow boiling heat transfer characteristics in a microchannel heat sink with various orientations

•Experiment on flow boiling under electric fields in an inclined microchannel has been carried out.•Effects of electric field/orientation on heat transfer coefficient are simultaneously discussed.•Mechanism of thermal performance enhancement by electric field/orientation is explored.•A new HTC asymptotic model introducing electric field force is developed on experimental data with an error of ±15%.