Method and device for simulating surface tension

1. A non-transitory computer-readable recording medium having stored therein a program for causing a computer to execute a process for simulating surface tension of a fluid, the process comprising:

determining, in accordance with a convex hull configuration algorithm, a calculated interface based on a fluid model expressing the fluid as a collection of liquid particles according to an input boundary condition and an initial condition;

calculating combined surface energy of the calculated interface by combining a first term representing first surface energy of a liquid-air interface, a second term representing second surface energy of a liquid-solid interface, and a third term that becomes infinite when a distance between a liquid particle and a solid is 0, each of the first and second terms including a surface tension coefficient changed while calculating the combined surface enemy of the calculated interface;

determining the surface tension of the calculated interface according to the combined surface energy;

determining a shape of the fluid, based on the surface tension, for each of sets of predetermined time intervals; and

representing the shape of the fluid during each of the sets of predetermined time intervals.

2. The non-transitory computer-readable recording medium according to claim 1 , wherein the calculating of the combined surface energy of the liquid-air interface adds a correction term to account for nonuniformity of surface distribution of the liquid particles of the fluid.

3. The non-transitory computer-readable recording medium according to claim 1 , wherein the calculating of the combined surface energy of the liquid-air interface adds a correction term to account for volume deformations of the fluid.

4. The non-transitory computer-readable recording medium according to claim 1 , wherein the fluid is at least one of a resin and a melted metal poured onto a solid surface.

5. The non-transitory computer-readable recording medium according to claim 4 , wherein the liquid-solid interface is between the fluid and the solid surface and the shape of the fluid represents the wettability of the solid surface.

6. The non-transitory computer-readable recording medium according to claim 5 , wherein the shape of the fluid is determined from a contact angle between the fluid and the solid surface calculated based on the fluid model.

7. A simulation method for simulating surface tension of a fluid, the simulation method comprising:

determining, in accordance with a convex hull configuration algorithm, a calculated interface based on a fluid model expressing the fluid as a collection of liquid particles according to an input boundary condition and an initial condition by a computer;

calculating combined surface energy of the calculated interface by combining a first term representing first surface energy of a liquid-air interface, a second term representing second surface energy of a liquid-solid interface, and a third term that becomes infinite when a distance between a liquid particle and a solid is 0, each of the first and second terms including a surface tension coefficient changed while calculating the combined surface energy of the calculated interface by the computer;

determining the surface tension of the calculated interface according to the combined surface energy by the computer;

determining a shape of the fluid, based on the surface tension, for each of sets of predetermined time intervals; and

representing the shape of the fluid during each of the sets of predetermined time intervals.

8. The simulation method according to claim 7 , wherein the fluid is at least one of a resin and a melted metal poured onto a solid surface.

9. The simulation method according to claim 8 , wherein the liquid-solid interface is between the fluid and the solid surface and the shape of the fluid represents the wettability of the solid surface.

10. The simulation method according to claim 9 , wherein the shape of the fluid is determined from a contact angle between the fluid and the solid surface calculated based on the fluid model.

11. A simulation device for simulating surface tension of a fluid, the simulation device comprising:

a processor configured to

determine, in accordance with a convex hull configuration algorithm, a calculated interface based on a fluid model expressing the fluid as a collection of liquid particles according to an input boundary condition and an initial condition,

calculate combined surface energy of the calculated interface by combining a first term representing first surface energy of a liquid-air interface, a second term representing second surface energy of a liquid-solid interface, and a third term that becomes infinite when a distance between a liquid particle and a solid is 0, each of the first and second terms including a surface tension coefficient changed while calculating the combined surface energy of the calculated interface,

determine the surface tension of the calculated interface according to the combined surface energy,

determine a shape of the fluid, based on the surface tension, for each of sets of predetermined time intervals; and

represent the shape of the fluid during each of the sets of predetermined time intervals.

12. The simulation device according to claim 11 , wherein the fluid is at least one of a resin and a melted metal poured onto a solid surface.

13. The simulation device according to claim 12 , wherein the liquid-solid interface is between the fluid and the solid surface and the shape of the fluid represents the wettability of the solid surface.

14. The simulation device according to claim 13 , wherein the shape of the fluid is determined from a contact angle between the fluid and the solid surface calculated based on the fluid model.