ORTHOGONAL GRID GENERATION FOR 2-DIMENSIONAL DUCTS

We present an orthogonal trajectory method for grid generation for two-dimensional ducts. The method can be seen as a generalization of the polar grid for a wedge or a circular annulus. Transversal grid lines are formed by arcs of circles and orthogonal trajectories are found by solving initial-value problems for ordinary differential equations. In order to have the method working, a condition involving the local width of the duct and the curvatures of the boundary curves must be satisfied. This condition is easily computable, and it should be checked in advance. For illustration several computational examples are included.