Patent ID: 7085695

Claim:
A method for simulating and analyzing fluid flow through at least a portion of, and ejection from, a channel, comprising the steps of: (a) setting a pressure indicative of the flow of a first fluid into the channel; (b) calculating, based on the inflow pressure of the first fluid, (i) the flow velocity of the first fluid through at least a portion of the channel, (ii) location of a triple point formed at the intersection of the first fluid, a second fluid and a wall of the channel, and (iii) a pressure related to the flow of the first fluid through the channel, wherein, in making the calculations in step (b), a free-slip boundary condition is imposed near the triple point allowing the triple point to move if a contact angle between the first fluid and a channel wall is greater than or equal to a first angle value or if the contact angle is less than or equal to a second angle value which is less than the first angle value, and an extra surface tension is included as a body force term in the calculation of the flow acceleration of the first fluid through at least the portion of the channel; and (c) simulating and displaying the flow of the first fluid through at least the portion of, and ejection from, the channel; and wherein, in the simulation, the first fluid represents ink, the second fluid represents air, and the channel represents an ink-jet nozzle that is part of a piezoelectric ink-jet head.