GEORGIA INSTITUTE OF TECHNOLOGY PROJECT TITLE: DETAILED MEASUREMENTS OF TURBULENT RAYLEIGH-TAYLOR AND RICHTMYER-MESHKOV MIXING AT EXTREME CONDITIONS PROJECT DESCRIPTION: IN EXTREME CONDITIONS, CHARACTERIZED BY LARGE MACH, ATWOOD AND SCHMIDT NUMBERS, THE MIXING PROCESS IN FLOWS OF INTEREST TO DOE-NNSA LABORATORIES IS HIGHLY INHOMOGENEOUS AND CHARACTERIZED BY MULTIPLE LENGTH AND TIME SCALES, DEPENDING ON MATERIAL PROPERTIES. THERE IS A STRONG NONLINEAR COUPLING BETWEEN THE MIXING PROCESS AND THE UNDERLYING TURBULENCE. DETAILED DATA FOR MISCIBLE FLUIDS, SUITABLE FOR INERTIAL CONFINEMENT FUSION (ICF) MODEL DEVELOPMENT AND VALIDATION, IS NOT AVAILABLE FOR MULTI-LAYER CONFIGURATIONS, TYPICAL OF ICF TARGETS. THE VISION OF THIS RENEWAL PROPOSAL IS TO USE NOVEL EXPERIMENTAL PLATFORMS AT THE GEORGIA TECH STAM LAB AND STATE-OF-THE-ART DIAGNOSTICS TO SIGNIFICANTLY ADVANCE THE UNDERSTANDING OF SHOCK- AND BUOYANCY-DRIVEN FLOWS AT EXTREME PARAMETER REGIMES (OF REYNOLDS NUMBER, MACH NUMBER, ATWOOD NUMBER). THE PROPOSED STUDIES OF HYDRODYNAMICS-DOMINATED MIXING (RAYLEIGH-TAYLOR, RICHTMYER-MESHKOV, AND KELVIN-HELMHOLTZ INSTABILITIES DRIVEN FLOWS) AND TURBULENCE UNDER THESE EXTREME CONDITIONS WILL ALLOW VALIDATION OF ENGINEERING MODELS FOR ICF TARGET DESIGN AND ENERGY DEPOSITION. RECENT TECHNOLOGICAL ADVANCES IN QUANTITATIVE HIGH-SPEED IMAGING WILL, FOR THE FIRST TIME, ALLOW US TO EXPERIMENTALLY QUANTIFY TEMPORALLY EVOLVING MULTI-SCALE INTERACTIONS BETWEEN FINE SCALE TURBULENCE, COHERENT STRUCTURES ASSOCIATED WITH UNDERLYING HYDRODYNAMIC INSTABILITIES AND SCALAR MIXING LAYERS. THE RESULT OF THIS RESEARCH WILL BE: (A) THE DEVELOPMENT OF RELIABLE EXPERIMENTAL DATA SETS FOR THE COMPLEX SET OF CONDITIONS DESCRIBED, WHICH WILL BE SHARED WITH THE NNSA COMMUNITY, AND (B) THE ADVANCEMENT OF THE THEORETICAL UNDERSTANDING OF THE DEVELOPMENT OF TURBULENCE IN INSTABILITY-DRIVEN FLOWS OF THE TYPE DESCRIBED, AND TO LEARN HOW TO BETTER MODEL THEM (C) THE DEVELOPMENT OF A NEW MULTI-PHYSICS PROBE (TEMPERATURE AND FLUORESCENCE) FOR MIXING STUDIES. THEIR STRONG TIES WITH LLNL AND LANL GIVE THEM A DIRECT PATHWAY FOR RESULTS AND INTERACTION (EXCHANGE OF STUDENTS, FACULTY, AND DATA). THE SCIENTIFIC OUTPUT WILL PROVIDE NNSA SCIENTISTS AT MULTIPLE INSTITUTIONS WITH BENCHMARK DATA TO SUPPORT THE VERIFICATION AND VALIDATION OF EXISTING NUMERICAL CODES AND ENHANCE THE DEVELOPMENT OF MORE PREDICTIVE MODELS FOR TURBULENT MIXING THAT SUPPORT DOE/NNSA’S PCF TECHNICAL OBJECTIVES. ASIDE FROM THE IMMEDIATE IMPACT ON ICF TARGET DESIGN, THE COLLECTION OF RT/RM/KH MIXING DATA HAS A BROAD IMPACT FOR PREDICTION OF OTHER BUOYANCY AND SHOCK-DRIVEN FLOWS SUCH AS CLIMATE, OCEANS, OIL RECOVERY (SALT-DOMES), SUPERSONIC MIXING AND FUEL SPRAY FORMATION. THUS, THIS PROPOSED RESEARCH SITS AS A CORNERSTONE TO FUNDAMENTAL SCIENCE THAT UNDERPINS ICF, ENERGY, AND CLIMATE.