Non-intrusive coupling of multi-physics codes for Eulerian-Lagrangian solid-solid interaction using Immersed Finite Element Method.
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Abstract not provided.
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Glass transition temperature measurement - telomer preparation and reactions
The SRM booster stage program cost estimate and time-phased funding requirements are presented in tabular form. Graphs on parametric analysis are also considered.
A baseline for a space shuttle configuration utilizing four parallel-burn 120-in. diameter SRMS is presented. Topics discussed include parachute system sequence, recovery system development profile, parachute container, and segment and closure recovery operations. A cost analysis for recovery of the SRM stage is presented. It is concluded that from the standpoint of minimum cost and development, parachutes are the best means of achieving SRM recovery. Major SRM components can be reused safely.
The baseline for a space shuttle configuration utilizing two parallel-burn, 156-in.-diameter SRMs with three segments and techroll seal movable nozzles is presented. The concept and general economic benefits of SRM recovery are equally valid for the series-burn SRMs, provided that those SRMs are also designed for the same strength, stiffness, segmentation, and interchangeability as the present design, and that those SRMs are also recovered as individual units. Feasibility studies were initiated to investigate SRM recoverability. These studies were based upon recovery of the SRM boosters for the Titan 3C. Ground rules precluded SRM modification that required significant changes in motor qualification or schedule. Even with this restriction, the study determined that the recoverable booster concept was completely feasible, both technically and economically. Parachute recovery has been selected as the best method, principally because it can accomplish the task with a minimum development cost and time to achieve operational recovery status. This system affords the highest probability for achieving large cost reductions.
The thermal stability of perchlorate composite propellants was studied at 135 and 170 C. The experimental efforts were concentrated on determining the importance of heterogeneous oxidizer-fuel reactions in the thermal degradation process. The experimental approach used to elucidate the mechanisms by which the oxidizer fuel composites thermally degrade was divided into two parts: (1) keeping the fuel constant and varying the nature of the oxidizers, and (2) holding the oxidizer constant and varying the fuel components. The fuel component primarily utilized in the first phase was polyethylene. Oxidizers included KClO4, KClO3, NH4ClO4 and NH4ClO4 doped with materials such as chlorate, phosphate and arsenate. In the second phase the oxidizer used was primarily NH4ClO4 while the fuels included saturated and unsaturated polybutadiene prepolymers and a series of bonding agents. Techniques employed in the current study include thermogravimetric measurements, differential thermal analysis, infrared, mass spectrometry, electron microscopy, and appropriate wet chemical analysis.
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A model is developed to predict the behavior of a thin fluid film in the wake of a tool in relative motion with respect to the table. Computational procedures are developed and limitations of the model are discussed. In general the fluid-interface temperature is controlled by conduction into the table. From the numerical results four regimes are identified: convective cooling, partial evaporation of the fluid film, extended evaporation due to a limiting evaporative heat flux, and surface dryout due to total evaporation of the fluid layer. These regimes are qualitatively illustrated in terms of the parameters film thickness, viscosity, and relative velocity.
To increase the success rate of U.S. built Rocket Motors (SRM), the approach taken is: (1) set common reliability goals for nozzles, cases, bondline, propellant, and insulation; (2) build a common engineering data base to support standard industry-wide reliability assessment models; (3) structure or enhance existing industry/government/user term to develop the tools, methods needed, and the data to support them; and (4) areas where unreliabilities are found must be improved.
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Solid-state batteries utilizing lithium metal anodes have the potential to enable batteries with a specific energy of >500 Wh/kg and an energy density of >1,500 Wh/L for thousands of cycles. When optimized they will improve the energy efficiency, operating temperature range, sustainability, and safety at a lower cost compared to projections for advanced Li-ion batteries. This improved performance is critical for the widespread adoption of electric vehicles and may enable future applications such as electric aviation. Expectations for solid-state batteries are high, there are significant materials and processing challenges that need to be overcome. Some of these challenges are well known; others are more subtle and are just becoming known. The challenges and their solutions must be clearly identified to realize high-energy solid-state Li metal batteries. In the United States, the U.S. Department of Energy (DOE) funds the majority of energy storage research and development, including solid state battery research. Web of Science publication analysis shows that worldwide DOE is second largest funder. Work on solid state batteries is distributed across different arms of DOE and is coordinated at headquarters to ensure a broad national portfolio for advanced batteries, including lithium batteries and solid-state battery devices. We note that university and national laboratory researchers in the US with a long-standing interest in solid state batteries is a small, integrated community with recognized impact for publications, patents and startup companies. The opportunity for this group to engage for research with international colleagues is growing, fostered by periodic bilateral meetings supported by DOE and by the recent joint US German research program for lithium battery interface studies. These are valuable opportunities to speed solid-state battery development. The ORNL led virtual workshop, overviewed here, confirms the community’s shared vision of the exciting advances, opportunities, and challenges. Further, we are seeing that this workshop has spawned several new informal collaborations and draft proposals. This encourages us to propose future discussion. On May 11, 2020, Oak Ridge National Laboratory (ORNL) hosted a 6-hour, on-line national workshop to discuss recent advances and most the prominent obstacles to realizing solid-state Li metal batteries. The workshop included more than 30+ experts from national laboratories, universities, and companies, all of whom have worked on solid-state batteries for multiple years. The participants shared recent advances, many not yet in print, illustrating that the community has gained significant new insights for solid-state Li battery materials over the last 5 years. In this report, the major outcomes of the workshop are organized to identify the gaps in our scientific knowledge for four core materials science areas: (1) Li metal anodes, (2) the solid electrolyte in contact with Li metal, (3) active cathode materials and solid-state composite cathodes, and (4) solid electrolytes. Illustrative examples and discussions are reported with the more comprehensive issues in the report. Discussion of additional challenges related to processing of solid-state battery materials and to the designs and architectures for mechanically robust, long-lived batteries received less attention due to time constraints. These are good themes for deeper discussion at a follow-on workshop, where a complete list of critical research topics can be identified.