TURBULENCE MODELLNG

A RESEARCH PROGRAM IS PROPOSED TO INVESTIGATE THE EMBODIED PHYSICS IN TURBULENCE CLOSURE MODELS IN ORDER TO DEVELOP A SINGLE MODULE FOR UTLLLZATLON INTO MULTI-ZONE NAVIER STOKES TYPE CODES. THE INVESTIGATION WILL FOCUS ON FUNDAMENTAL PARALLEL SHEAR FLOWS WITH CONSIDERATION TO WALL CONDITIONS THAT INCLUDE ROUGHNESS. MASS TRANSFER, PRESSURE GRADIENT, AND LOW REYNOLDS NUMBER EFFECTS. MOREOVER, THE DEVELOPMENT OF A MODEL THAT FEATURES UNIVERSALITY WILL CONSIDER GENERALIZATION OF EXISTING TECHNIQUES BASED ON LOW-SPEED TURBULENCE MODELS AND PHYSICAL EVIDENCE TO PROVIDE NEAR TERM PREDICTION CAPABILITY. THE UNISTRY/SAIC APPROACH FEATURES A BUILDING-BLOCK METHODOLOGY BASED ON THE TEAMS EXTENSIVE EXPERIENCE IN CODE DEVELOPMENT AND APPLICATLON WHICH REQUIRES A THOROUGH KNOWLEDGE OF TURBULENCE CLOSURE TECHNIQUES. THIS APPROACH IDENTIFIES FLOW DOMAINS APPLICABLE TO VARIOUS CLOSURE MODELS (WITH MODIFICATIONS) FROM WHICH THE LOGIC TO DEVELOP CLOSURE COEFFICIENTS WHERE LENGTH SCALES OF TURBULENCE CAN BE ASSESSED. SPECIFIC ATTENTION WILL BE GIVEN TO UNIT PROBLEMS (ROUGHNESS FOR EXAMPLE) AS WELL AS COUPLING OF UNIT PROBLEMS WHICH HAS NOT BEEN DEMONSTRATED IN THE LITERATURE. THE TEAMS UNDERSTANDING AND USE OF THE VARIOUS TECHNIQUES, AS PROVIDED ON THE NASP, ALLOWS FOR AN IMPARTIAL ASSESSMENT FROM A USER POINT-OF-VIEW.