"DEVELOPMENT OF A ROBUST NONEQUILIBRIUM PARABOLIZED NAVIER-STOKES CODE"

THE GOAL OF THIS RESEARCH IS TO PRODUCE A NEW, REAL GAS, THREE-DIMENSIONAL, PARABOLIZED NAVIER-STOKES (PNS) CODE WHICH IS MORE ROBUST, MORE ACCURATE, AND EASIER TO USE THAN THOSE PRESENTLY IN EXISTENCE. MOST "CURRENT DAY" PNS CODES (INCLUDING THE AFWAL PNS CODE) ARE BASED ON THE NONITERATIVE, IMPLICIT BEAM-WARMING FINITE-DIFFERENCE SCHEME. UNFORTUNATELY, CODES OF THIS TYPE HAVE PROVEN TO BEUNRELIABLE AT TIMES AS A RESULT OF THE CENTRAL DIFFERENCING AND APPROXIMATE FACTORIZATION WHICH ARE EMPLOYED IN THE NUMERICAL SCHEME. IN THE PROPOSED RESEARCH, A NEW, REAL GAS, PNS CODE WILL BE DEVELOPED BASED ON ROE'S UPWIND SCHEME. THE NATURAL DISSIPATION ASSOCIATED WITH THIS SCHEMEIS SUFFICIENTLY ADAPTIVE TO LOCAL FLOW CONDITIONS THAT NO ADDITIONAL "SMOOTHING" IS REQUIRED EVEN IN THE PRESENCE OF VERY STRONG SHOCK WAVES. THE NEW PNS CODE WILL PERMIT EITHER PERFECT GAS, EQUILIBRIUM, OR NONEQUILIBRIUM CALCULATIONS TO BE PERFORMED. FOR THE NONEQUILIBRIUM CALCULATIONS, THE FINITE-RATE CHEMISTRY WILL BE DIRECTLY COUPLED WITH THE FLUID DYNAMICS IN A NONITERATIVE MANNER. DURING PHASE I, A TWO-DIMENSIONAL/AXIALLY SYMMETRIC VERSION OF THE CODE WILL BE DEVELOPED. UTILIZING THE EXPERIENCE GAINED FROM PHASE I, A FULLY THREE-DIMENSIONAL CODE WILL BE PRODUCED IN PHASE II.