Cahn Hilliard phase-field method is used to numerically simulate subcooled water boiling in which nucleation occurs from an artificial cavity on the inner surface of a microchannel. The boiling initiates from a cavity and the growth and departure of the nucleated bubbles from the cavity are simulated. The velocity, temperature and pressure distributions inside the microchannel have been analyzed. The bubble generation frequency increases by increasing inlet mass flux. For this case of study, the rising trend continues up to the mass flux of 64 kg/m(2) s. Further increase in the inlet mass flux does not accelerate the bubble formation. The radius and the shape of the generated bubble compared well with experimental data available in the literature. (C) 2016 Elsevier Ltd. All rights reserved.