COMPUTATIONAL MODELING OF 3-D UNSTEADY FLOW

A USER-FRIENDLY COMPUTER CODE WILL BE DEVELOPED TO CALCULATE THE UNSTEADY AND HIGHLY 3-D COMPLEX FLOWPATHS IN EXHAUST DIFFUSERS OF MODERN MARINE GAS TURBINES, INCLUDING PRESSURE LOSSES AND NONUNIFORM FLOW LOSSES. THE VAX-VMS CODE WILL BE BASED UPON AN EXISTING 3-D TIME-DEPENDENT NAVIER-STOKES CODE ALREADY VALIDATED IN THE CALCULATION OF PITCHING OF A SWEPT WING SECTION MOUNTED IN A WIND TUNNEL, AND RECENTLY EXTENDED UNDER SEPARATE NAVY FUNDING TO INCOMPRESSIBLE FLOWS AND TO INCLUDE VARIATIONAL BOUNDARY FITTED AND SOLUTION ADAPTIVE GRID GENERATION. THE EFFICIENT IMPLICIT CODE USES AND AF (APPROXIMATE FACTORIZATION) ALGORITHM WHICH IS SECOND ORDER ACCURATE (INCLUDING CROSS DERIVATIVE TERMS). THE NEW CODE WILL INCLUDE TURBULENCE MODELING FOR STRONGLY SEPARATED RECIRCULATING FLOWS, AUTOMATIC ERROR ESTIMATION, AND USER-FRIENDLY GEOMETRY DESCRIPTION APPROPRIATE TO CONICAL (AND GENERAL) EXHAUST DIFFUSERS WITH DUMP-TYPE COLLECTOR BOXES. THE USER-FRIENDLY INTERFACE WILL UTILIZE A FORTRAN PORTABLE NAME-LIST DEVELOPED AT ECODYNAMICS.