Generating a simulated fluid flow over an aircraft surface using anisotropic diffusion

A computer-implemented method of generating a fluid-flow simulation over a computer-generated aircraft surface, the surface comprised of a surface mesh of polygons, the method comprising:

• determining a pressure-gradient vector for a selected polygon, the selected polygon belonging to the surface mesh of polygons;
• defining a minimum diffusion rate along the direction of the pressure gradient vector of the selected polygon;
• defining a maximum diffusion rate in a direction perpendicular to the direction of the pressure gradient vector of the selected polygon;
• defining a diffusion-path vector from a point in the selected polygon to a neighboring point in a neighboring polygon, the neighboring polygon belonging to the surface mesh of polygons;
• and
• determining an updated fluid property for the selected polygon using a variable diffusion rate, the variable diffusion rate based on the minimum diffusion rate, maximum diffusion rate, and angular difference between the diffusion-path vector and the pressure gradient vector.

A non-transitory computer-readable medium storing computer-readable instructions for generating a fluid-flow simulation over a computer-generated aircraft surface, the surface comprised of a surface mesh of polygons, the instructions for:

• obtaining a boundary-layer fluid property for a subset of the polygons of the surface mesh of polygons, the subset of polygons representing a portion of the computer-generated aircraft surface;
• determining a pressure-gradient vector for a selected polygon, the selected polygon belonging to the surface mesh of polygons but not one of the subset of polygons for which a boundary-layer fluid property has been obtained;
• defining a minimum diffusion rate along the direction of the pressure gradient vector of the selected polygon;
• defining a maximum diffusion rate in a direction perpendicular to the direction of the pressure gradient vector of the selected polygon;
• defining a diffusion-path vector from a point in the selected polygon to a neighboring point in a neighboring polygon, the neighboring polygon belonging to the subset of polygons for which a boundary-layer fluid property has been obtained;
• and
• determining an updated fluid property for the selected polygon using a variable diffusion rate, the variable diffusion rate based on the minimum diffusion rate, maximum diffusion rate, and angular difference between the diffusion-path vector and the pressure gradient vector.

A non-transitory computer-readable medium storing computer-readable instructions for generating a fluid-flow simulation over a computer-generated aircraft surface, the surface comprised of a surface mesh of polygons, the instructions for:

• determining a pressure-gradient vector for a selected polygon, the selected polygon belonging to the surface mesh of polygons;
• defining a minimum diffusion rate along the direction of the pressure gradient vector of the selected polygon;
• defining a maximum diffusion rate in a direction perpendicular to the direction of the pressure gradient vector of the selected polygon;
• defining a diffusion-path vector from a point in the selected polygon to a neighboring point in a neighboring polygon, the neighboring polygon belonging to the surface mesh of polygons;
• and
• determining an updated fluid property for the selected polygon using a variable diffusion rate, the variable diffusion rate based on the minimum diffusion rate, maximum diffusion rate, and angular difference between the diffusion-path vector and the pressure gradient vector.