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DoD High Performance Computing Modernization Program Users Group Conference, 2007

Date 18-21 June 2007

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  • HPCMP Users Group Conference 2007 - Cover

    Publication Year: 2007 , Page(s): c1
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  • HPCMP Users Group Conference 2007 - Title page

    Publication Year: 2007 , Page(s): i - iii
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  • HPCMP Users Group Conference 2007 - Copyright

    Publication Year: 2007 , Page(s): iv
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  • HPCMP Users Group Conference 2007 - TOC

    Publication Year: 2007 , Page(s): v - ix
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  • Editors Preface

    Publication Year: 2007 , Page(s): x - xi
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  • Abstract authors index

    Publication Year: 2007
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  • A Computational Study of Detonation of Propagation in PBX-9404 Using CTH and LASmerf Codes

    Publication Year: 2007 , Page(s): 3 - 6
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (130 KB) |  | HTML iconHTML  

    For many years, the researchers at the Army Research Laboratory (ARL) have been using CTH hydrocode and its History Variable Reactive Burn (HVRB) model to study the reactive behavior of various granular and non-granular explosives. Recently, we acquired another code (LASmerf) to study the response of the munitions. A computational study was undertaken to compare the results from these two codes. A comparison of the computational results will be presented in this paper. Also, a brief description, advantages, and disadvantages of each code will be discussed. View full abstract»

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  • Breaching of Triple-Brick Walls: Numerical Simulations

    Publication Year: 2007 , Page(s): 7 - 11
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (416 KB) |  | HTML iconHTML  

    Explosive wall breaching will be a key war-fighter capability in future military operations by dismounted soldiers in urban terrain environments where the close proximity of urban structures, possibly occupied by noncombatants, significantly restricts the use of large demolition charges or large caliber direct-fire weapons. Because of this requirement, the US Army has focused considerable attention and resources to optimize breaching activities in urban terrain. As part of the Army's effort, the US Army engineer research and development center (ERDC) is conducting experimental and numerical investigations to improve wall breaching methods. The ongoing experimental and numerical programs will conduct comprehensive breaching research on a full range of urban construction materials. As a first step in this process, the ERDC conducted a successful baseline study of Composition C4 (C-4) breaching effectiveness against steel-reinforced-concrete walls. Recently, the research effort was extended to triple-brick walls. Numerical simulations of two selected experiments were conducted using the coupled Eulerian- Lagrangian code Zapotec. In these simulations, the brick and mortar were modeled as Lagrangian materials, and the C-4 was modeled as an Eulerian material. View full abstract»

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  • Statistical Fatigue and Residual Strength Analysis of New/Aging Aircraft Structure

    Publication Year: 2007 , Page(s): 12 - 17
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    The paper describes an ongoing work with populating the world's largest stress intensity factor data base with 92.4 million new solutions and separate work consisting of large-scale residual strength analysis of the C-130 center-wing-box (CWB) considering numerous different multiple-crack crack configurations. A computationally efficient and reliable procedure is used for calculating stress intensity factor solutions K(y) to be stored in the data base. An extended technique is used in predicting the residual strength of the C-130 CWB for multiple crack configurations. The proposed method requires a method/solver that can solve the very complex nonlinear contact problems between rivets and the skin/stiffeners, failure of rivets with a very low computational cost per crack configuration. The splitting scheme described in the paper is the basic tool used to obtain this objective. All mathematical equations are solved with high accuracy with respect to the exact mathematical solution of the problem and with control of the point-wise error (less than 1%) in all stress intensity functions K(y). For residual strength analysis of the CWB, the software used scales very well on computer hardware like SGI Altix (ASC/Eagle/Hawk) and IBM P5 (NAVO/Babbage/Kraken). Several three-dimensional analyses representative of the size and complexity of the C-130 center wing box have been completed. An example of such an analysis explicitly modeled the wing skins, spar caps, spar webs, and stringers which resulted in 90 million nodes and 14 million finite elements. Depending on the polynomial order, p, used in the solution, the total degrees of freedom ranges from 243-742 million for polynomial orders p = 2 - 4; respectively. For a more accurate solution polynomial order, 5 is needed which results in a problem with 1.2 billions of degrees-of freedom. View full abstract»

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  • Applied Computational Fluid Dynamics in Support of Aircraft/Store Compatibility and Weapons Integration-2007 Edition

    Publication Year: 2007 , Page(s): 21 - 27
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (395 KB) |  | HTML iconHTML  

    The Air Force SEEK EAGLE Office (AFSEO), Eglin AFB, FL, is the United States Air Force (USAF) authority for weapons certification efforts. AFSEO performs test and evaluation for aircraft/store compatibility certification. Computational fluid dynamics (CFD) is employed to support this process. Determining the flow about an aircraft/store combination can be extremely difficult. Complicated geometry features such as pylons, launchers, grid fins, and internal weapons bays create severe aerothermodynamic and acoustic environments which are challenging to numerically simulate. Rapidly and accurately modeling the trajectory of store separation in a high-volume simulation environment presents an additional challenge. The USAF requirement for numerous, simultaneous and quick-reaction solutions for a wide variety of stores and aircraft can only be accomplished through application of parallel high performance computing resources that meet the significant computational and memory demands associated with the certification computational environment. Before operational use, all aircraft/store configurations must be certified for safe loading, carriage and jettison/release. AFSEO provides flight certification recommendations which are based on combinations of engineering analysis, ground, and flight testing. Engineering analyses is provided by disciplines in carriage loads, store separations, flutter, ballistics, stability and control, and electromagnetic compatibility, and interference. The AFSEO Computational Aeromechanics Team provides time-critical CFD support for engineering analyses to optimize ground and flight testing. This contribution takes the form of carriage aerodynamic loads, store separation predictions, and visualized flow field physics. The knowledge created reduces risk, lowers cost, and speeds the fielding of new weapons. This paper discusses six of the most recently applied AFSEO CFD tasks related to specific aircraft/store investigations and certifications. View full abstract»

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  • Characterization of High Altitude Turbulence for Air Force Platforms

    Publication Year: 2007 , Page(s): 28 - 32
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (370 KB) |  | HTML iconHTML  

    The Department of Defense (DoD) has an urgent need to both understand and predict the effects of high-altitude (z > 10 km) turbulence (HAT) on systems that operate at or propagate through those altitudes. Examples of systems affected by HAT include surveillance aircraft such as the U-2 and the unmanned Global Hawk, developing weapons systems such as the airborne laser (ABL), and developing communication systems such as the transformational communication satellites (TSAT). The surveillance aircraft are primarily affected by mechanical turbulence, which is the fluctuation of wind velocity and is usually caused by velocity gradients, flow over terrain, or convection. High frequency gravity waves can affect the aircraft the same way and are caused by the same forcing mechanisms as actual mechanical turbulence and are considered as part of the HAT forecast problem. The effects of mechanical turbulence include upsetting the autopilot, degrading the quality of the surveillance observations, and in the worse case jeopardizing the aircraft itself. Laser-based systems such as the ABL and TSAT are affected by optical turbulence, which is the fluctuation of the index of refraction and is caused by mechanical turbulence in the presence of temperature gradients. For directed-energy weapon systems such as the ABL, optical turbulence causes the laser to wander, spread, and scintillate which will degrade its power, result in increased dwell time to destroy a target, and decrease the effective range. For laser-based communication systems such as TSAT, optical turbulence can result in significant data dropouts. View full abstract»

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  • Computations of a Maneuvering Unmanned Combat Air Vehicle Using a High-Order Overset Grid Method

    Publication Year: 2007 , Page(s): 33 - 40
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (450 KB) |  | HTML iconHTML  

    Simulating the flow around a maneuvering unmanned combat air vehicle (UCAV) requires a computational method capable of modeling such complex flow features as massive separation, transition from laminar to turbulent flow, and nonlinear vortex dynamics. In the present paper, a parallel, high-order, overset-grid solver is used to compute these challenging flowfields. Turbulence modeling is accomplished using an implicit Large Eddy Simulation (LES) approach, which exploits the characteristics of the sixth-order accurate computational scheme coupled with high-order, low pass filtering. This scheme provides a unified computational approach for the laminar/transitional/turbulent flowfields encountered by maneuvering UCAVs. A general overset- grid capability, including high-order interpolation and the ability to handle holes while maintaining high-order accuracy, has been incorporated into the flow solver. This high-order method is applied to the simulation of a canonical low sweep delta wing and a generic, tailless, low-sweep wing UCAV configuration. Computations performed for the low sweep delta wing at moderate Reynolds numbers demonstrate the ability of the implicit large-eddy simulation (ILES) approach to capture important Reynolds number effects for these complicated transitional flowfields. Groundbreaking high-order computations for the generic UCAV configuration are then presented with the fundamental aerodynamic phenomena of the configuration being examined using the improved accuracy of the high-order overset method. Comparisons with available experimental measurements are made to demonstrate the ability of this high-fidelity modeling approach to capture the complex flow physics involved. View full abstract»

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  • High Resolution Simulation of Full Aircraft Control at Flight Reynolds Numbers

    Publication Year: 2007 , Page(s): 41 - 47
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (481 KB) |  | HTML iconHTML  

    This paper documents interim results of a three year project to develop a computational method for accurately determining static and dynamic stability and control characteristics of fighter and transport aircraft with various store configurations, as well as the aircraft response to pilot input. In this second year of the project computational data is gathered for a rigid F-16C with no control surface movement in forced motion that approximates flight test maneuvers. "Computational maneuvers" designed to efficiently gather three axes of motion data to build a comprehensive reduced order model are also developed. The data is then post- processed to determine the resulting static and dynamic stability characteristics. The main benefits of this effort are: 1) early discovery of complex aerodynamic phenomena that are typically only present in dynamic flight maneuvers and therefore not discovered until flight test, and 2) rapid generation of an accurate aerodynamic database to support aircraft and weapon certification by reducing required flight test hours and complementing current stability and control testing. View full abstract»

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  • HPC Enhancement of Plume Modeling for Use by Military Simulators

    Publication Year: 2007 , Page(s): 48 - 51
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (415 KB) |  | HTML iconHTML  

    An application programming interface (API) was developed to make CT-Analyst's high fidelity physics based plume predictions available to modeling and simulation (M&S) tools. This plume API was used with the M&S application one semi-automated forces (OneSAF). OneSAF is a next generation entity level simulation. For a 10 by 5 km region of Baghdad, OneSAF made use of CT-Analyst through the application programming interface (API) to determine the plume locations, the plume concentration at points within the simulation, and to determine the attenuation of visibility along a line. Before the simulation is run, FAST3D-CT generates a pre-computed Nomograf database. During the simulation, OneSAF calls a CT-Analyst process that in turn interprets the Nomograf database to generate plumes. View full abstract»

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  • Lattice Boltzmann Algorithms for Fluid Turbulence

    Publication Year: 2007 , Page(s): 52 - 56
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (304 KB) |  | HTML iconHTML  

    Lattice Boltzmann algorihms are a mesoscopic representation of nonlinear continuum physics (like Navier-Stokes, magnetohydro dynamics (MHD), Gross- Pitaevskii equations) which are ideal for parallel supercomputers because they transform the difficult nonlinear convective macroscopic derivatives into purely local moments of distribution functions. The macroscopic nonlinearities are recovered by relaxation distribution functions in the collision operator whose dependence on the macroscopic velocity is algebraically nonlinear and thus purely local. Unlike standard computational fluid dynamics codes, there is no loss in parallelization in handling arbitrary geometric boundaries, e.g., using bounce-back rules from kinetic theory. By encoding detailed balance into the collision operator through the introduction of discrete H-function, the lattice Boltzmann algorithm can be made unconditionally stable for arbitrary high Reynolds numbers. It is shown that this approach is a special case of a quantum lattice Boltzmann algorithm that entangles local qubits through unitary collision operators and which is ideally parallelized on quantum computer architectures. Here we consider turbulence simulations using 2,048 PEs on a 1,6003-spatial grid. A connection is found between the rate of change of enstrophy and the onset of laminar-to- turbulent flows. View full abstract»

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  • Multi-Scale Predictability of High-Impact Stratospheric Clear Air Turbulence Events for Air Force Platforms

    Publication Year: 2007 , Page(s): 57 - 63
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2222 KB) |  | HTML iconHTML  

    Vertical nesting and adaptive vertical gridding in nested mesoscale weather research and forecasting (WRF)/microscale codes are developed. The inner nest of WRF is coupled with a sequence of embedded microscale nests, both horizontally and vertically. The fully three-dimensional (3D), compressible Navier-Stokes equations are solved with a stretched, adaptive grid in the vertical, with grid spacing down to a few meters in thin clear air turbulence (CAT) layers where strong turbulent mixing occurs. For nesting, both lateral and vertical boundary conditions are treated via relaxation zones where the velocity and temperature fields are relaxed to those obtained from the WRF inner nest. This methodology is applied to the analysis of field data from T-REX campaign of measurements. Real case simulations based on initial and boundary conditions from high resolution T799 L91 European centre for medium-range weather forecasts (ECMWF) analysis data are conducted. The embedded microscale nests predict localized shear layers and diagnose stiff gradients of vertical velocity and potential temperature above the tropopause and in the lower stratosphere. Three-dimensional instability mechanisms and turbulent dynamics within these CAT layers are fully resolved. View full abstract»

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  • Time-Accurate Calculations of Free-Flight Aerodynamics of Maneuvering Projectiles

    Publication Year: 2007 , Page(s): 64 - 69
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (508 KB) |  | HTML iconHTML  

    This paper describes a multidisciplinary computational study undertaken to model the flight trajectories and the free-flight aerodynamics of finned projectiles both with and without control maneuvers. Advanced computational capabilities both in computational fluid dynamics (CFD) and rigid body dynamics (RBD) have been successfully fully coupled on high performance computing (HPC) platforms for "virtual fly-outs" of munitions similar to actual free flight tests in the aerodynamic experimental facilities. Time-accurate Navier-Stokes computations have been performed to compute the unsteady aerodynamics associated with the free flight of a finned projectile at a supersonic speed using an advanced scalable unstructured flow solver on a highly parallel Linux cluster. Some results relating to the portability and the performance of the flow solver on the Linux clusters are also addressed. Computed positions and orientations of the projectile along the flight trajectory have been compared with actual data measured from free flight tests and are found to be generally in good agreement. Computed results obtained for another complex finned configuration with canard-control pitch-up maneuver in a virtual fly-out show the potential of these techniques for providing the actual time-dependent response of the flight vehicle and the resulting unsteady aerodynamics for maneuvering projectiles. View full abstract»

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  • Active Flow Control of Low-Pressure Turbine Separation

    Publication Year: 2007 , Page(s): 73 - 82
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (965 KB) |  | HTML iconHTML  

    Operating low-pressure turbines (LPT) at off-design conditions or considering more aggressive designs can lead to laminar separation on the suction side of the LPT blades resulting in significant turbine and overall engine performance losses. In these instances, performance improvements may be achieved with active flow control (AFC). In an extensive experimental research program at the Air Force Research Laboratory (AFRL) at Wright-Patterson AFB, Dr. R.B. Rivir and co-workers systematically investigated the benefits of AFC with steady and pulsed vortex generator jets (VGJs) for a linear PakB LPT cascade. Pulsed VGJs were found to be very effective in mitigating separation. We are employing two in-house computational fluid dynamics (CFD) research codes for investigating the physical mechanisms associated with AFC for LPT geometries. For simulations of the entire LPT blade, a high-order-accurate finite volume code based on the compressible Navier-Stokes equations is used. Data from direct numerical simulations (DNS) with up to 19.4 million grid points of a PakB blade at Re=25,000 are compared with experimental data. For our fully resolved DNS that focus exclusively on the separated flow region, we are employing a high-order-accurate compact finite difference code based on the incompressible Navier-Stokes equations in vorticity-velocity formulation. Here, we study a separation bubble on a flat plate and on a curved wall model-geometry under LPT conditions. These simulations enable us to identify the intricate physical mechanisms associated with unsteady separation, transition, flow instabilities, and active control using VGJs. In particular, our simulation results provide an explanation for the stunning effectiveness of pulsed VGJs for separation control. View full abstract»

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  • Combustion Chamber Fluid Dynamics and Hypergolic Gel Propellant Chemistry Simulations for Selectable Thrust Rocket Engines

    Publication Year: 2007 , Page(s): 83 - 88
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (304 KB) |  | HTML iconHTML  

    This paper describes the application of high performance computing to accelerate the development of hypergolic propulsion systems for tactical missiles. Computational fluid dynamics is employed to model the chemically reacting flow within a system's combustion chamber, and computational chemistry is employed to characterize propellant physical and reactive properties. Accomplishments from the past year are presented and discussed. View full abstract»

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  • Computational Investigations of Air Entrainment, Hysteresis, and Loading for Large-Scale, Buoyant Cavities

    Publication Year: 2007 , Page(s): 89 - 97
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (576 KB) |  | HTML iconHTML  

    A complete physical model of ventilated supercavitation is not well established. Efforts documented display the ability, with a finite volume, locally homogeneous approach, to simulate supercavitating flows and obtain good agreement with experiments. Several modeling requirements appear critical, especially in physical hysteretic conditions or configurations. The hysteresis presented is due to obstruction of the flow with a solid object. The modeling approach taken correctly captures a full hysteresis loop and the corresponding dimensionless ventilation rate to cavity pressure (CQdelta) relationship. This correspondence supports the suggestion that the main mechanism of cavity gas entrainment is via shear layers attached to the cavity walls. With such validated solutions, additional insight into the flow within the cavity is gained. View full abstract»

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  • Computational Modeling of the CH-47 Helicopter in Hover

    Publication Year: 2007 , Page(s): 98 - 103
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (290 KB) |  | HTML iconHTML  

    This paper describes installed rotor performance computations for the CH-47 Chinook tandem-rotor helicopter. The computations were performed with a Reynolds-Averaged Navier-Stokes flow solver using overset structured grids to resolve the flow around the rotors, the fuselage, and the resulting rotor wake system. The calculations model all six rotor blades discretely while resolving the rotor motions relative to the fuselage in a time-accurate manner. The computational performance predictions are compared to Boeing flight test data and show good agreement with the experimental measurements. In addition, the computational results provide a wealth of data on the interactions between the rotor wake system and the fuselage that can't be easily obtained in any other way. View full abstract»

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  • Direct Quantum Mechanical Simulations of Shocked Energetic Materials Supporting Future Force Insensitive Munitions Requirements

    Publication Year: 2007 , Page(s): 104 - 109
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (271 KB) |  | HTML iconHTML  

    Quantum mechanical calculations based on density functional theory (DFT) are used to study dynamic behavior of shocked polymeric nitrogen, a novel energetic material. We report results on system sizes in excess of 3,000 atoms. Such calculations on system sizes within the 1,000 atom range remain problematic using standard implementations of DFT. We evaluate the feasibility of using several available DFT codes for this work through comparison of scalability and resource requirements. In this study, we utilize a recently developed highly-scalable localized orbital DFT code, CP2K, designed to treat large systems. Scaling and performance benchmarks of the CP2K on several Department of Defense (DoD) high performance computing (HPC) computers are presented for a variety of system sizes and shapes. Additionally, we report preliminary calculations on the conventional explosive nitromethane. In those calculations in excess of 3,500, atoms are treated. View full abstract»

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  • Effect of Curved Radial Vane Cavity Arrangements on Predicted Inter-Turbine Burner (ITB) Performance

    Publication Year: 2007 , Page(s): 110 - 119
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1237 KB) |  | HTML iconHTML  

    The demand for significantly higher performance gas turbine engines has led to the exploration and identification of "out of the box" innovative engine design concepts. These demands include increased thrust-to-weight ratio goals that can primarily be met by substantial engine performance increases such as specific thrust, engine weight and size reductions, and repackaging of engine components to create compact engines. Concepts of an ultra-compact-combustor (UCC) for use as a main combustor, or as an inter-turbine burner (ITB) to boost engine work output, reduce pollutant emissions and engine weight are being explored. The available experimental results and observations indicate that UCC/ITB can operate at 95-99% combustion efficiency over a wide range of operating conditions and with flame lengths up to 50% shorter than those of conventional combustors. In the present study the radial curved vane ITB design concept has been modeled using three-dimensional computational fluid dynamics (CFD). The objectives are to predict ITB flow field and combustion characteristics, guide ITB experimental investigations, identify the key design parameters driving performance, and use the results to optimize ITB design configurations. The CFD predictions demonstrated that intense burning in a high-g loaded cavity occurred which resulted in high combustion efficiency. Models with the radial vane cavity located in both the suction and pressure side have been developed. The circumferential cavity air is injected through the air injection tubes into the circumferential cavity. The orientation of this injection is used to create both a clock-wise (CW) and a counter-clock-wise (CCW) direction of circumferential flow in the outer cavity, when looking upstream from the aft end of the ITB configuration. The resulting five candidate configurations have been simulated and analyzed in detail. This study indicates improved exit profile characteristics for the curved radial vane (CRV) with the c- avity in the suction side and the air injected in the CCW direction, compared to the pressure side cavity with air injected either in CCW or CW direction and CRV with no cavity. View full abstract»

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  • Fast and Accurate CBR Defense for Homeland Security: Bringing HPC to the First Responder and Warfighter

    Publication Year: 2007 , Page(s): 120 - 126
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (183 KB) |  | HTML iconHTML  

    An urban-oriented emergency assessment system for airborne chemical, biological, and radiological (CBR) threats, called CT-Analystreg and based on new principles, gives greater accuracy and much greater speed than possible with current alternatives. The increased accuracy derives from detailed, three-dimensional (3D) computational fluid dynamics (CFD) computations including, solar heating, buoyancy, complete building geometry specification, trees, and wind fluctuations. A limited number of such detailed high performance computing (HPC) computations for a given area can be extended to all wind directions and speeds, and all likely sources and source locations using a new data structure called Dispersion Nomografstrade. By performing all the heavy computing ahead of time using the full power of HPC parallel platforms well suited to the application, the results of a number of complete, high-resolution 3D simulations can be recalled for operational usage with no sensible delay for integration of even simple models. In this way, we have solved the usual dilemma of more computer time being required to obtain better answers. The best available answers can be presented instantly with full urban geometry in a readily comprehended format. View full abstract»

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  • Integrated Analysis of Scramjet Flowpath with Innovative Inlets

    Publication Year: 2007 , Page(s): 127 - 132
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (813 KB) |  | HTML iconHTML  

    Significant progress has been achieved during the first year of this Challenge effort, in developing and simulating configurations which highlight the main scramjet inlet flow path alternatives. In particular, three different types of inward-turning inlets have been explored, including the rectangular cross-section, scoop and "jaws" designs. Each flowpath has been discretized and subjected to inviscid, laminar and turbulent analyses with highly-scalable solvers at design and off-design conditions ranging from Mach 6 to Mach 10. Viscous/inviscid interactions are observed to have a profound impact on the flow, giving rise to distortion of the velocity profile at the exit of the inlet (entrance of the isolator/combustor component). For the jaws approach, the effects of angle-of-attack and yaw have been studied. A complex pattern of low and high total pressure variation is observed, suggesting strategies for the subsequent fuel injection processes. For the rectangular cross-section dual-plane compression inlet, combustor integration has been accomplished with finite-rate chemical kinetics. The effect on mixing characteristics of numerous injection strategies, both upstream and/or in the interior of a wall cavity, are examined. The injection process is observed to yield a separation shock, bow shock and Mach disk, as well as a reattachment shock. Potential phenomena that might generate instabilities and subsequent unstart have been identified, as are locations of high temperature, unburnt fuel gases and combustion efficiency. In a separate, but related effort, simulations have also been performed to yield data for flight-test experiments (HiFIRE program) to ensure survivability of mass capture diagnostic devices. View full abstract»

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