AN IMPLICIT FINITE DIFFERENCE SOLUTION FOR JET AND WAKE PROBLEMS. PART I: ANALYSIS AND TEST CASES

A solution of the describing equations for chemically non-reacting 2-D symmetric and axisymmetric jet and wake problems was obtained in the boundary layer approximations by an implicit finite difference scheme which permits arbitrary initial and boundary conditions and assumptions for transport properties. The species equation was included in order to analyze the heterogeneous mixing of two dissimilar gases. Initial profiles, measured in detail, are used to march downstream, satisfying the boundary conditions at infinity and at the plane or axis of symmetry at each axial station. The solution is valid in laminar as well as turbulent flow. Flow fields with pressure gradients were taken into account. The scheme, being implicit in form, is free from stability difficulties; it always converges and has a smaller truncation error compared to the explicit schemes and, therefore, permits larger step sizes in the analysis. Several numerical examples were included to demonstrate the application of the method. (Author) See also Part 2, AD-707 866.