Boundary Rothogonality in Higenstock-white

G. Sun

I have a problem about redistribution the control function in elliptic grid generation near the corner boundary. The Higenstock-white control function is

P(n+1) = p(n)-tanh(pi/2-theta)

q(n+1) = q(n)+tanh(d(eta)-d(eta(n))) this method can distribution grid line orthogonality using pi/2 for whole grid line, but nera the corner, the angle between the grid line is not pi/2. How to deal with it?