Parabolic flows in which the pressure variation in the streamwise (or
marching) direction is unknown a priori include internal thin shear la
yers, shock-boundary layer interactions, and in verse boundary layers
with specified displacement thickness or shear stress. The pressure is
typically obtained through an additional iteration beyond that requir
ed to determine the velocity components (and other dependent variables
). A generalized block-tridiagonal procedure is discussed in which pre
ssure is determined within the iteration for velocity components to su
bstantially reduce computation time. The increase in algebraic complex
ity in the solution procedure is small; no increase in the size of the
block matrices is required. The method applies to any marching soluti
on in which a scalar dependent variable is constant across the flow, b
ut varies in the streamwise or marching direction.