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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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All sourcesNASA NTRSDOE OSTI
NASA NTRSDate not supplied

SIBatt-3D: In-Space/On-Surface 3D Printing of Sodium Ion Batteries from ISRU Materials

Constructed more than 20 years ago, the International Space Station’s primary power system originally used nickel-hydrogen batteries with a lifetime of 6.5 years, until NASA began the process of replacing them in 2016 with lithium-ion batteries with a lifetime of 10 years. The demanding and costly process was accomplished after four flights of the Japanese H-II Transfer Vehicle cargo spacecraft (with a cost of about $10,000 per pound of payload), and 13 different astronauts conducting 14 spacewalks. Besides utilization in the ISS, rechargeable batteries are present in many space applications: they are installed in exploration robots, life support systems and in portable communication devices, to mention some. In this context, this project is focused on the in-space manufacturing of shape-conformable batteries using in-situ resources, and aims to address the NASA’s gaps related to the development of next generation of energy storage devices (TX03), as well as in-space manufacturing and in-situ resource utilization (TX07). The proposed work also tackles the HEOMD’s objectives targeting the in-space additive manufacturing (AM) from Lunar/Martian materials (regolith as AM feedstock) to reinvigorate America’s Human Space Exploration Program (SPD-1). This project is in direct alignment with the STMD’s objectives to demonstrate in-space autonomous manufacturing and assembly of complete systems by 2030, and to enable humans to live and explore in space and on planetary surfaces by 2040 thanks to in-space habitation, infrastructure development and in-situ resource utilization (ST1 and ST5). Manufacturing of shape conformable batteries directly in-space and using in-situ resources would also contribute to reducing the payload weight and volume (TX12) for future missions, thus reducing risk for long term Mars missions where rapid resupply is logistically infeasible. Nowadays, commercial batteries consist of stacked two-dimensional (2D) sheets, which are only manufactured in restricted geometries (cylindrical and coin cell). Evolving from conventional 2D, complex 3D battery architectures have been proven to increase the electrochemical active surface area and ion diffusion path, leading to improved areal energy density and power performance. This tendency was illustrated in our recent in-depth modeling studies by simulating a classical Ragone plot exhibiting the energy-power relationship. Our team demonstrated through modeling that a complex gyroidal 3D printed battery architecture exhibits significantly improved power performances (>150% at the current density of 6C; full discharge in 10 minutes) in comparison to a traditional 3D printed planar geometry. Motivated by these results and as the fabrication of intricate 3D battery design is only possible experimentally thanks to the geometric freedom offered by additive manufacturing (AM), our team has already initiated leveraging thermoplastic material extrusion at the laboratory scale. While 3D printing of batteries is relatively recent (2013), it has witnessed a growing interest during the last recent years, as next-generation shape-conformable 3D batteries can be co-designed with the system. Consequently, dead-volume and mass brought from Earth are minimized, in addition to improved battery performance, in alignment with the aforementioned NASA’s objectives. Further, while this project is specifically dedicated to batteries, it lends itself towards the maturation of in-space manufacturing via 3D printing using in-situ resources, stated in HEOMD and STMD goals.

In-Space Manufacturing↗
NASA NTRS1979

The dispersed fluorescence spectrum of NaAr - Ground and excited state potential curves

Potential curves for the ground state and the first excited state of NaAr were determined. The van der Waals molecule NaAr was prepared by supersonic free jet expansion of a mixture of sodium, argon, and helium. The electronic transition from the ground state to the first excited state A2pi was excited by a tunable dye laser and the resulting fluorescence was studied. The dispersed fluorescence spectra show discrete and diffuse features, corresponding to transitions from excited vibrational levels of the A state to bound and unbound levels of the x state. The characteristic reflection structure in the bound-free spectra permits an unambiguous assignment of the vibrational numbering in the A state, and this assignment together with previously measured spectroscopic constants are used to calculate the potential curve of the A state. The discrete structure in the fluorescence spectra is used to determine the potential curve of the x state in the well region, and the repulsive part of the X curve is then deduced through trial-and-error simulation of the bound-free spectra.

Tellinghuisen, J.↗
NASA NTRS1993

Effects of geometric nonlinearities on the response of optimized box beam structures

The present minimum-mass designs for a two-spar rectangular box beam were derived on the basis of linear-buckling FEM analysis constraints. In order to ascertain the effects of any geometric nonlinearities on these designs, each was subjected to a geometrically nonlinear FEM analysis. In all cases, the structure collapses below the design load, and does so in a mode which differs from that of linear theory. This discrepancy is attributable to such nonlinear panel-interaction mechanisms as rib-crusing loads. The optimized design is highly sensitive to crushing loads, relative to the nonoptimal design.

Ragon, S.↗
NASA NTRS1995

Optimization of composite box-beam structures including effects of subcomponent interactions

Minimum mass designs are obtained for a simple box beam structure subject to bending, torque and combined bending/torque load cases. These designs are obtained subject to point strain and linear buckling constraints. The present work differs from previous efforts in that special attention is payed to including the effects of subcomponent panel interaction in the optimal design process. Two different approaches are used to impose the buckling constraints. When the global approach is used, buckling constraints are imposed on the global structure via a linear eigenvalue analysis. This approach allows the subcomponent panels to interact in a realistic manner. The results obtained using this approach are compared to results obtained using a traditional, less expensive approach, called the local approach. When the local approach is used, in-plane loads are extracted from the global model and used to impose buckling constraints on each subcomponent panel individually. In the global cases, it is found that there can be significant interaction between skin, spar, and rib design variables. This coupling is weak or nonexistent in the local designs. It is determined that weight savings of up to 7% may be obtained by using the global approach instead of the local approach to design these structures. Several of the designs obtained using the linear buckling analysis are subjected to a geometrically nonlinear analysis. For the designs which were subjected to bending loads, the innermost rib panel begins to collapse at less than half the intended design load and in a mode different from that predicted by linear analysis. The discrepancy between the predicted linear and nonlinear responses is attributed to the effects of the nonlinear rib crushing load, and the parameter which controls this rib collapse failure mode is shown to be the rib thickness. The rib collapse failure mode may be avoided by increasing the rib thickness above the value obtained from the (linear analysis based) optimizer. It is concluded that it would be necessary to include geometric nonlinearities in the design optimization process if the true optimum in this case were to be found.

Ragon, Scott A.↗
NASA NTRS1999

Design Optimization of Stiffened Panels with Postbuckling Constraints

The funding provided by the grant is used to complete the final stages of the development of a geometrically nonlinear analysis and design capability for the static response of compressively loaded prismatic plate structures. The analysis is based on the nonlinear finite strip method and is applicable for structures, such as stiffened panels or box columns, that can be modeled as assemblages of finite length plate strips. In an effort to reduce the computational cost of the nonlinear finite strip method, thus making it suitable for use in the design optimization environment, reduced basis techniques as described in various references by Noor are used in conjunction with the finite strip method. In addition, an efficient scheme for tracing the nonlinear equilibrium paths through highly nonlinear response curves was implemented. The new scheme, which is referred to as the normal flow algorithm, is based on homotopy methods, and is capable of negotiating highly nonlinear limit point instabilities with a reduced computational cost compared to the popular Ricks/Wempner and Chrisfield algorithms.

Guerdal, Zafer↗
NASA NTRS2004

Flexible Approximation Model Approach for Bi-Level Integrated System Synthesis

Bi-Level Integrated System Synthesis (BLISS) is an approach that allows design problems to be naturally decomposed into a set of subsystem optimizations and a single system optimization. In the BLISS approach, approximate mathematical models are used to transfer information from the subsystem optimizations to the system optimization. Accurate approximation models are therefore critical to the success of the BLISS procedure. In this paper, new capabilities that are being developed to generate accurate approximation models for BLISS procedure will be described. The benefits of using flexible approximation models such as Kriging will be demonstrated in terms of convergence characteristics and computational cost. An approach of dealing with cases where subsystem optimization cannot find a feasible design will be investigated by using the new flexible approximation models for the violated local constraints.

Sobieszczanski-Sobieski, Jaroslaw↗
NASA NTRS2005

A Parallel Trade Study Architecture for Design Optimization of Complex Systems

Design of a successful product requires evaluating many design alternatives in a limited design cycle time. This can be achieved through leveraging design space exploration tools and available computing resources on the network. This paper presents a parallel trade study architecture to integrate trade study clients and computing resources on a network using Web services. The parallel trade study solution is demonstrated to accelerate design of experiments, genetic algorithm optimization, and a cost as an independent variable (CAIV) study for a space system application.

Kim, Hongman↗