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Publications
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📜 Development of modeling capabilities for launch pad acoustics and ignition transient environment prediction
J. S. West, L. L. Strutzenberg, G. C. Putnam, P. Liever, and B. Williams. 18th AIAA/CEAS Aeroacoustics Conference (33rd AIAA Aeroacoustics Conference), p. 2094.
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| 🕵🏻 | J. S. West, L. L. Strutzenberg, G. C. Putnam, P. Liever, and B. Williams. |
| 📚 | 18th AIAA/CEAS Aeroacoustics Conference (33rd AIAA Aeroacoustics Conference) |
| 📖 | p. 2094. |
| 📆 | June 4th, 2012 |
| 📜 | This paper presents the development effort to establish modeling capabilities for launch vehicle liftoff acoustics and ignition transient environment predictions. Peak acoustic loads experienced by the launch vehicle occur during liftoff with strong interaction between the vehicle and the launch facility. Acoustic prediction engineering tools based on empirical models are of limited value in efforts to proactively design and optimize launch vehicles and launch facility configurations for liftoff acoustics. Modeling approaches are needed that capture the important details of the plume flow environment including the ignition transient, identify the noise generation sources and allow assessment of the effects of launch pad geometric details and acoustic mitigation measures such as water injection. This paper will present a status of the CFD tools developed by the Marshall Space Flight Center (MSFC) Fluid Dynamics Branch featuring relevant advanced multi-physics modeling capabilities and related efforts to establish a hybrid acoustic environment modeling capability combining CFD with a Boundary Element Method (BEM) acoustic field propagation model. |
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2012 |
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📜 Numerical modeling of solid rocket motor plumes
M Mehta, B Williams, GC Putnam, SD Smith, 2012 Thermal and Fluids Workshop, Pasadena, CA
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| 🕵🏻 | M. Mehta, B. Williams, G. C. Putnam, S. D. Smith |
| 📚 | 2012 Thermal and Fluids Workshop, Pasadena, CA |
| 📖 | p. 38 |
| 📆 | August 2012 |
| 📜 | In support of prediction of the launch pad plume deflector environments during solid rocket booster derived NASA STS (Space Shuttle) vehicle ascent, the solid rocket motor plumes have been successfully modeled and analyzed with the Loci-CHEM Navier-Stokes computational fluid dynamics (CFD) code - Lagrangian Model at a steady-state approximation. Three main areas have been addressed in this paper: (1) sensitivity study of the Loci-CHEM-Lagrangian model with various other Loci-CHEM modeling approaches; (2) in-depth analysis of the aerophysics associated with solid rocket motor plumes; (3) comparison studies between the CFD numerical simulations and flight data and an independent engineering code, Reacting and Multi-Phase Program (RAMP2). The reusable solid rocket motor plumes are a multi-phase flow which contains both plume gases and ~16% solid aluminum oxide particles by mass. This contribution of solid particles is shown to have a large impact on the aerophysics of the plume gases and the environments of the launch pad plume deflector. The Loci-CHEM–Lagrangian model shows the best overall agreement with plume deflector flight data and the RAMP2 engineering code. These modeling approaches are being implemented to conduct higher fidelity numerical simulations for the Space Launch System ascent and launch pad environments. |
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2012 |
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📜 Curved Waveguide Based Nuclear Fission for Small, Lightweight Reactors
R Coker, G Putnam, 19th Advanced Space Propulsion Workshop, NASA George C. Marshall Space Flight Center, Huntsville, AL, no. M12-2257.
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| 🕵🏻 | R. Coker, G. C. Putnam |
| 📚 | 19th Advanced Space Propulsion Workshop |
| 📖 | no. M12-2257. |
| 📆 | November 27th, 2012 |
| 📜 | The focus of the presented work is on the creation of a system of grazing incidence, supermirror waveguides for the capture and reuse of fission sourced neutrons. Within research reactors, neutron guides are a well known tool for directing neutrons from the confined and hazardous central core to a more accessible testing or measurement location. Typical neutron guides have rectangular, hollow cross sections, which are crafted as thin, mirrored waveguides plated with metal (commonly nickel). Under glancing angles with incoming neutrons, these waveguides can achieve nearly lossless transport of neutrons to distant instruments. Furthermore, recent developments have created supermirror surfaces which can accommodate neutron grazing angles up to four times as steep as nickel. A completed system will form an enclosing ring or spherical resonator system to a coupled neutron source for the purpose of capturing and reusing free neutrons to sustain and/or accelerate fission. While grazing incidence mirrors are a known method of directing and safely using neutrons, no method has been disclosed for capture and reuse of neutrons or sustainment of fission using a circular waveguide structure. The presented work is in the process of fabricating a functional, highly curved, neutron supermirror using known methods of Ni-Ti layering capable of achieving incident reflection angles up to four times steeper than nickel alone. Parallel work is analytically investigating future geometries, mirror compositions, and sources for enabling sustained fission with applicability to the propulsion and energy goals of NASA and other agencies. Should research into this concept prove feasible, it would lead to development of a high energy density, low mass power source potentially capable of sustaining fission with a fraction of the standard critical mass for a given material and a broadening of feasible materials due to reduced rates of release, absorption, and non-fission for neutrons. This advance could be applied to direct propulsion through guided fission products or as a secondary energy source for high impulse electric propulsion. It would help meet national needs for highly efficient energy sources with limited dependence on fossil fuels or conflict materials, and it would improve the use of low grade fissile materials which would help reduce national stockpiles and waste. |
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2012 |
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📜 Validation and Simulation of ARES I Scale Model Acoustic Test - 1 - Pathfinder Development
G. C. Putnam, JANNAF 8th Modeling and Simulation Subcommittee Meeting, NASA George C. Marshall Space Flight Center, Huntsville, AL, no. M11-0635.
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| 🕵🏻 | G. C. Putnam |
| 📚 | JANNAF 8th Modeling and Simulation Subcommittee Meeting |
| 📖 | no. M11-0635. |
| 📆 | December 5th, 2011 |
| 📜 | The Ares I Scale Model Acoustics Test (ASMAT) is a series of live-fire tests of scaled rocket motors meant to simulate the conditions of the Ares I launch configuration. These tests have provided a well documented set of high fidelity measurements useful for validation including data taken over a range of test conditions and containing phenomena like Ignition Over-Pressure and water suppression of acoustics. To take advantage of this data, a digital representation of the ASMAT test setup has been constructed and test firings of the motor have been simulated using the Loci/CHEM computational fluid dynamics software. Within this first of a series of papers, results from ASMAT simulations with the rocket in a held down configuration and without water suppression have then been compared to acoustic data collected from similar live-fire tests to assess the accuracy of the simulations. Detailed evaluations of the mesh features, mesh length scales relative to acoustic signals, Courant-Friedrichs-Lewy numbers, and spatial residual sources have been performed to support this assessment. Results of acoustic comparisons have shown good correlation with the amplitude and temporal shape of pressure features and reasonable spectral accuracy up to approximately 1000 Hz. Major plume and acoustic features have been well captured including the plume shock structure, the igniter pulse transient, and the ignition overpressure. Finally, acoustic propagation patterns illustrated a previously unconsidered issue of tower placement inline with the high intensity overpressure propagation path. |
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2011 |
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📜 Validation and Simulation of Ares I Scale Model Acoustic Test - 2 - Simulations at 5 Foot Elevation for Evaluation of Launch Mount Effects
G. C. Putnam, JANNAF 5th Spacecraft Propulsion Subcommittee Meeting, NASA George C. Marshall Space Flight Center, Huntsville, AL, no. M11-0653.
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| 🕵🏻 | L. L. Strutzenberg, G. C. Putnam |
| 📚 | JANNAF 5th Spacecraft Propulsion Subcommittee Meeting |
| 📖 | no. M11-0653. |
| 📆 | December 5th, 2011 |
| 📜 | The Ares I Scale Model Acoustics Test (ASMAT) is a series of live-fire tests of scaled rocket motors meant to simulate the conditions of the Ares I launch configuration. These tests have provided a well documented set of high fidelity measurements useful for validation including data taken over a range of test conditions and containing phenomena like Ignition Over-Pressure and water suppression of acoustics. Expanding from initial simulations of the ASMAT setup in a held down configuration, simulations have been performed using the Loci/CHEM computational fluid dynamics software for ASMAT tests of the vehicle at 5 ft. elevation (100 ft. real vehicle elevation) with worst case drift in the direction of the launch tower. These tests have been performed without water suppression and have compared the acoustic emissions for launch structures with and without launch mounts. In addition, simulation results have also been compared to acoustic and imagery data collected from similar live-fire tests to assess the accuracy of the simulations. Simulations have shown a marked change in the pattern of emissions after removal of the launch mount with a reduction in the overall acoustic environment experienced by the vehicle and the formation of highly directed acoustic waves moving across the platform deck. Comparisons of simulation results to live-fire test data showed good amplitude and temporal correlation and imagery comparisons over the visible and infrared wavelengths showed qualitative capture of all plume and pressure wave evolution features. |
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2011 |
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📜 Validation and Simulation of Ares I Scale Model Acoustic Test - 3 - Modeling and Evaluating the Effect of Rainbird Water Deluge Inclusion
G. C. Putnam, JANNAF 8th Modeling and Simulation Subcommittee Meeting, NASA George C. Marshall Space Flight Center, Huntsville, AL, no. M11-0657.
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| 🕵🏻 | L. L. Strutzenberg, G. C. Putnam |
| 📚 | JANNAF 8th Modeling and Simulation Subcommittee Meeting |
| 📖 | no. M11-0657. |
| 📆 | December 5th, 2011 |
| 📜 | The Ares I Scale Model Acoustics Test (ASMAT) is a series of live-fire tests of scaled rocket motors meant to simulate the conditions of the Ares I launch configuration. These tests have provided a well documented set of high fidelity measurements useful for validation including data taken over a range of test conditions and containing phenomena like Ignition Over-Pressure and water suppression of acoustics. Building on dry simulations of the ASMAT tests with the vehicle at 5 ft. elevation (100 ft. real vehicle elevation), wet simulations of the ASMAT test setup have been performed using the Loci/CHEM computational fluid dynamics software to explore the effect of rainbird water suppression inclusion on the launch platform deck. Two-phase water simulation has been performed using an energy and mass coupled lagrangian particle system module where liquid phase emissions are segregated into clouds of virtual particles and gas phase mass transfer is accomplished through simple Weber number controlled breakup and boiling models. Comparisons have been performed to the dry 5 ft. elevation cases, using configurations with and without launch mounts. These cases have been used to explore the interaction between rainbird spray patterns and launch mount geometry and evaluate the acoustic sound pressure level knockdown achieved through above-deck rainbird deluge inclusion. This comparison has been anchored with validation from live-fire test data which showed a reduction in rainbird effectiveness with the presence of a launch mount. |
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2011 |
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📜 Simulation of Ares Scale Model Acoustic Test Overpressure Transients Using Computational Fluid Dynamics
G. C. Putnam, 162nd Acoustical Society of America (ASA) Meeting, San Diego, CA, Paper M11, Volume 1226
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| 🕵🏻 | G. C. Putnam |
| 📚 | 162nd Acoustical Society of America (ASA) Meeting, San Diego, CA |
| 📖 | Paper M11, Volume 1226 |
| 📆 | November 3rd, 2011 |
| 📜 | Outline • Introduction – Overview of the Ares Scale Model Acoustic Test (ASMAT) – Simulation goal and procedure • Case Progression – Initial Attempt at Elevation 0’ (Pathfinder) – Ignition Transient and Throat Plug Release – Model Refinement • Conclusions / Future Work 2 Page 3 Introduction : ASMAT Overview • Ares Scale Model Acoustic Test – Tests of 5% scale model of Ares I vehicle – Addressed vibration / acoustic risks from Constellation Program. • Physical Test Setup – Scale model powered by Rocket Assisted Take-Off (RATO) motor – Vehicle at point of, or just after, lift-off – Stationary in space during firing – 100+ pressure transducers on the launch structure and vehicle (locations later) • Simulation Interest – Well documented set of high fidelity measurements for CFD validation – Demonstration of CFD capability for IOP prediction … |
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2011 |
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📜 To Profit or Not: Economic Considerations of Long Term Organizations
G. C. Putnam, Defense Advanced Research Projects Agency: 100 Year Starship Symposium, Education, Society, Legal and Economic Panel, 2:45
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| 🕵🏻 | G. C. Putnam |
| 📚 | Defense Advanced Research Projects Agency: 100 Year Starship Symposium |
| 📖 | Education, Society, Legal and Economic Panel, 2:45 |
| 📆 | October 1st, 2011 |
| 📜 | ESELC Summary: Education as a mission, Who goes, who stays, To profit or not, Economies in space, Communications back to Earth, Political ramifications, Round-trip legacy investments – assets left behind |
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2011 |
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📜 Simulation of acoustics for Ares I scale model acoustic tests
G. C. Putnam, L. L. Strutzenburg, The Journal of the Acoustical Society of America, Volume 130, Issue 4, p. 2543-2543
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| 🕵🏻 | G. C. Putnam, L. L. Strutzenburg |
| 📚 | The Journal of the Acoustical Society of America |
| 📖 | Volume 130, Issue 4, p. 2543-2543 |
| 📆 | October, 2011 |
| 📜 | The Ares I scale model acoustics test (ASMAT) is a series of live-fire tests of scaled rocket motors meant to simulate the conditions of the Ares I launch configuration. These tests have provided a well documented set of high fidelity acoustic measurements useful for validation including data taken over a range of test conditions and containing phenomena like ignition over-pressure and water suppression of acoustics. To take advantage of this data, a digital representation of the ASMAT test setup has been constructed and test firings of the motor have been simulated using the Loci/CHEM computational fluid dynamics software. Results from ASMAT simulations with the rocket in both held down and elevated configurations, as well as with and without water suppression have been compared to acoustic data collected from similar live-fire tests. Results of acoustic comparisons have shown good correlation with the amplitude and temporal shape of pressure features and reasonable spectral accuracy up to approximately 1000 Hz. Major plume and acoustic features have been well captured including the plume shock structure, the igniter pulse transient, and the ignition overpressure. |
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2011 |
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📜 Ultrasonic particle size fractionation in a moving air stream
R. S. Budwig, M. J. Anderson, G. C. Putnam, C. Manning, Ultrasonics, Volume 50, Issue 1, p. 26-31
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| 🕵🏻 | R. S. Budwig, M. J. Anderson, G. C. Putnam, C. Manning |
| 📚 | Ultrasonics |
| 📖 | Volume 50, Issue 1, p. 26-31 |
| 📆 | January 1st, 2010 |
| 📜 | Identification of bio-aerosol particles may be enhanced by size sorting before applying analytical techniques. In this paper, the use of ultrasonic acoustic radiation pressure to continuously size fractionate particles in a moving air stream is described. Separate particle-laden and clean air streams are introduced into a channel and merged under laminar flow conditions. An ultrasonic transducer, mounted flush to one wall of the channel, excites a standing ultrasonic wave perpendicular to the flow of the combined air stream. Acoustic radiation forces on the particles cause them to move transverse to the flow direction. Since the radiation force is dependent upon the particle size, larger particles move a greater transverse distance as they pass through the standing wave. The outlet flow is then separated into streams, each containing a range of particle sizes. Experiments were performed with air streams containing glass microspheres with a size distribution from 2–22 μm, using a centerline air stream velocity of approximately 20 cm/s. An electrostatic transducer operating at a nominal frequency of 50 kHz was used to drive an ultrasonic standing wave of 150 dB in pressure amplitude. The microsphere size distributions measured at the outlet were compared with the predictions of a theoretical model. Experiments and theory show reasonable correspondence. The theoretical model also indicates an optimal partitioning of the particle-laden and clean air inlet streams. |
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2010 |
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📜 Use of a curved reflector to amplify ultrasonic standing waves in an air-filled channel
M. J. Anderson, A. C. Cluff, E. C. Lemmon, G. C. Putnam, The Journal of the Acoustical Society of America, Volume 117, Issue 3, p. 1122-1128
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| 🕵🏻 | M. J. Anderson, A. C. Cluff, E. C. Lemmon, G. C. Putnam |
| 📚 | The Journal of the Acoustical Society of America |
| 📖 | Volume 117, Issue 3, p. 1122-1128 |
| 📆 | March, 2005 |
| 📜 | The application of a slightly curved reflector to increase the amplitude of an ultrasonic standing wave in a semi-infinite rectangular channel was explored. Air was assumed to be the acoustic medium in the channel. Excitation of the standing wave was assumed to be provided by a square transducer flush-mounted to one wall of the channel. A slight curvature was placed in the reflecting wall of the channel. A finite element analysis was used to predict the amplitude of the standing wave that would be excited in the channel. A perfectly matched layer was used to model the semi-infinite channel geometry. At frequencies near 50 kHz, for source ranging from 6.6 to 26.6, and channel depths necessary to excite standing waves at one-half and one wavelength resonance, the computations predicted that an increase in acoustic pressure amplitude from 2 to 11 dB could be achieved with a reflector whose depth of curvature was 16% of the channel depth. Much of this increase could be obtained with curvatures of smaller depth. Experiments with a channel and reflector of representative geometry gave a measured increase in acoustic pressure amplitude of 4.86 dB. |
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2005 |
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📜 Use of a slightly curved reflector to enhance an airborne ultrasonic standing wave in a semi‐infinite rectangular channel
M. J. Anderson, A. C. Cluff, E. C. Lemmon, G. C. Putnam, The Journal of the Acoustical Society of America, Volume 116, Issue 4, p. 2598-2598
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| 🕵🏻 | M. J. Anderson, A. C. Cluff, E. C. Lemmon, G. C. Putnam |
| 📚 | The Journal of the Acoustical Society of America |
| 📖 | Volume 116, Issue 4, p. 2598-2598 |
| 📆 | October, 2004 |
| 📜 | One way to separate small particles from a moving air stream is to pass the stream through an intense ultrasonic standing wave. If the standing wave propagates perpendicular to the fluid flow direction, acoustic radiation pressure will move the particles to specific locations in the stream, where they can be collected at the stream outlet. Of primary importance is to achieve very high pressure amplitude in the standing wave, in spite of the presence of openings for fluid flow. In this presentation, the use of a slightly curved reflector within a flow channel to increase the amplitude of an ultrasonic standing wave is discussed. A finite element analysis was used to predict the amplitude of the standing wave that would be excited in a semi‐infinite channel. A perfectly matched layer was used to account for the semi‐infinite geometry. The finite element analysis showed that a significant gain in amplification within the channel could be achieved with a surprisingly small amount of reflector curvature. Experiments show that much of this gain can be obtained in practice. |
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2004 |
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📜 An Optimization Study for the Separation of Particles in Air Using Acoustic Resonance
G. C. Putnam, University of Idaho, Master's Thesis, Dept. of Mechanical Engineering, Moscow, Idaho, USA
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| 🕵🏻 | G. C. Putnam |
| 📚 | University of Idaho |
| 📖 | Master's Thesis |
| 📆 | June, 2004 |
| 📜 | Acoustic amplification within a partially enclosed cavity has a number of uses in applications where mass must enter and leave the cavity. This work describes an optimization process, which was used to maximize the performance of such a cavity for use in separation of airborne particulates. The acoustic source of the cavity, the shape of the reflector used within the cavity, and the paths of particles flowing through the cavity were all investigated. It was found that for frequencies in the vicinity of 50 kHz, electrostatic transducers can be designed which provide significant gains in acoustic resonant pressure and quality factor over conventional Polaroid and piezoelectric technologies. It was also noted that for curved reflector technologies, the presence of a curved reflector did improve both pressure and quality factors. However, the achievable experimental gains were significantly less than those predicted through theoretical models. Finally, it was found that when implemented within a model resonator, the presence of a curved reflector induced little unwanted particle motion within the flow and significantly improved separation performance. |
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2004 |
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📜 The physics and technology of ultrasonic particle separation in air
M. J. Anderson, R. S. Budwig, A. C. Cluff, E. C. Lemmon, G. C. Putnam, Proceedings of the 2003 World Congress on Ultrasonics, Paris, p. 1615-1621
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| 🕵🏻 | M. J. Anderson, R. S. Budwig, A. C. Cluff, E. C. Lemmon, G. C. Putnam |
| 📚 | Proceedings of the 2003 World Congress on Ultrasonics, Paris |
| 📖 | p. 1615-1621 |
| 📆 | September 7th-10th, 2003 |
| 📜 | A potential application of ultrasound is the separation of small particles from a moving airborne aerosol. Previous studies have shown that it is feasible to extract small particles from a moving stream of water. The thermodynamic and transport properties of the suspension fluid control the mechanisms available for separation, the forces that can be exerted, and the practical dimensions of ultrasonic airborne particle separators. Fundamental models exist that allow comparison of electrostatic and piezoelectric transduction in general for ultrasonic particle separation. Finite element studies show that allowance for slight curvatures in flow channel geometry can increase achievable acoustic pressures. We describe analyses and experiments that consider these factors for ultrasonic particle separation in air. The potential performance of ultrasonic separation in air is then compared to competing inertial technologies. |
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2003 |
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Conference Demos
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🎪 SC12, Reaching Beyond Low Earth Orbit
G. C. Putnam, B. Williams, P. Davis, Supercomputing 12, Salt Lake City, Utah, NASA@SC12 Booth
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| 🕵🏻 | G. C. Putnam, B. Williams, P. Davis |
| 📚 | Supercomputing 12, Salt Lake City, Utah |
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| 📖 | NASA@SC12 Booth |
| 📆 | November 10th-16th, 2012 |
| 📜 | Using thousands of processors on the Pleiades supercomputer at the NASA Advanced Supercomputing Division (NAS) at Ames Research Center, Moffett Field, Calif., the MSFC Fluid Dynamics team ran more than 40 CFD simulations, each spanning several weeks and requiring multiple terabytes of storage to process hundreds of individual gigabyte-scale files for visualization, post-processing, and data analysis. These simulations capture the sources of the acoustic waves and follow the action to track their effects throughout the launch environment. Validated results are provided to SLS engineers so they can optimize the design of the vehicle and launch components. |
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2012 |
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🎪 SC12, Simulating Rocket Ignition and Launch Environments for NASA's Space Launch System
G. C. Putnam, Supercomputing 12, Salt Lake City, Utah, NASA@SC12 Booth
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| 🕵🏻 | G. C. Putnam |
| 📚 | Supercomputing 12, Salt Lake City, Utah |
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| 📖 | NASA@SC12 Booth |
| 📆 | November 10th-16th, 2012 |
| 📜 | During liftoff, the Space Launch System's (SLS) solid rocket boosters (SRBs) send large amplitude pressure waves into the confined space of the launch structure. These ignition overpressure (IOP) waves, which radiate throughout the launch environment, can cause damage to the launch structure, the vehicle, and the payload, and must be well understood during the design process. Rocket plume gas and evaporating suppression water interact as the ignition overpressure (IOP) wave propagates through the launch tower. The validation provided confidence that CFD methods could accurately predict phenomena such as IOP in the full-scale SLS launch environment. The full-scale analysis was decoupled into component problems that could be simulated and validated independently, then used to inform simulations of the full-scale integrated vehicle. The first component problem examined the propagation of acoustic waves through the launch environment. The simulations tracked the propagation of acoustic waves in both dry launch pad conditions and in conditions with water-based sound suppression systems activated. The second component performed time-accurate, fully 3D simulations of the SRB ignition transient and was used to create a time-dependent profile the rocket internal dynamics as an input to further simulations for SLS launch-induced environments. Finally, using the results of the sub-scale and SRB simulations, full-scale simulations were performed of the SLS launch environment with the goal of resolving tool uncertainties that could not account for differences from the Shuttle to SLS configuration. |
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2012 |
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🎪 SC12, Validating Water Spray Simulation Models for the SLS Launch Environment
G. C. Putnam, Supercomputing 12, Salt Lake City, Utah, NASA@SC12 Booth
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| 🕵🏻 | G. C. Putnam |
| 📚 | Supercomputing 12, Salt Lake City, Utah |
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| 📖 | NASA@SC12 Booth |
| 📆 | November 10th-16th, 2012 |
| 📜 | Validations against recent NASA test data have shown that modern Computational Fluid Dynamics (CFD) codes can make meaningful pressure predictions over the full launch pad for frequencies up to 150 Hz, high enough that significant phenomena such as the transient startup and overpressure pulse of rockets can be modeled. These validations have provided confidence in the results of CFD simulations, allowing them to make immediate impacts on the design of NASA's new Space Launch System (SLS). Modifications to the mobile launcher, flame deflector, vehicle base, and liftoff design have all been influenced by this work. However, simulations have been limited in their validation and use to dry launch pads. To examine the full range of designs, multi-phase capability has been developed in partnership with Mississippi State University and used to simulate the effects of water suppression for a wet launch pad validation case. Emission, flight, and evaporation of water spray systems have been simulated on an active launch pad by using a two-phase approach that includes Lagrangian water particles and gas phase CFD elements. The simulation was based on a test case from the Ares I Scale Model Acoustic Test so that pressure predictions from across the launch pad could be validated against real data. Approximately 200 million grid cells were used to capture the fine detail and geometry of the pad, and millions of particles were tracked to capture the dynamics of a water cascade. This work was performed using a density-based, finite-volume CFD code called Loci/CHEM. |
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2012 |
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🎪 SC11, Simulating the Ares I Scale Model Acoustic Test Using CFD
G. C. Putnam, Supercomputing 11, Seattle, Washington, NASA@SC11 Booth
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| 🕵🏻 | G. C. Putnam |
| 📚 | Supercomputing 11, Seattle, Washington |
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| 📖 | NASA@SC11 Booth |
| 📆 | November 12th-18th, 2011 |
| 📜 | NASA regularly uses computational fluid dynamics (CFD) simulations to assess the loads and risks for space vehicles at liftoff. To have confidence in the results from these simulations, however, their accuracy must be anchored to real-world measurements. Recently, such validations have been performed using data from Ares I scaled rocket tests at Marshall Space Flight Center. The Ares I Scale Model Acoustics Test (ASMAT) was a series of live-fire tests of a scaled rocket motor intended to simulate the acoustic conditions of the full Ares I vehicle at launch. The test's primary goals were to validate the acoustic environment and loads of the vehicle. Simulations of the ASMAT motor firings were performed before live-fire tests to predict the rocket performance and the startup environment at liftoff. Results from the simulations have been compared to a range of pressure measurements from the physical test setup, as well as to visible and infrared imagery of the tests, and have shown excellent correlation to real-world results. These initial findings have helped provide the confidence to move forward with full-scale simulations of liftoff environments for future launch vehicles, such as the Space Launch System. |
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2011 |
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