throughout the liquid.
Inside an equilateral triangle, for instance, of height h,
[psi]´ = -2R[alpha][beta][gamma]/h, (8)
where [alpha], [beta], [gamma] are the perpendiculars on the sides of
the triangle.
In the general case [psi]´ = [psi] + Uy - Vx + ½R(x² + y²) is the
relative stream function for velocity components, U, V, R.