Search NASA⌕ Search

SEARCH · Search NASA

Results for “Design Patterns”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 397 records · Page 22
All sourcesNASA NTRSDOE OSTI
NASA NTRS2018

En Route Detect and Avoid Well Clear in Terminal Area Landing Pattern

A fast time simulation was conducted to test the detect and avoid Well Clear definition designed for en route use when an unmanned aircraft (UA) is approaching the landing pattern of the terminal area. Measures focused on were loss of well clear and alerts intended to help the pilot avoid loss of well clear. Data indicated warning-level alerts will occur outside the typical Class D airspace which may prevent the UA from normal operations in the terminal airspace. Other aircraft on 45o entry could result in “nuisance” alerts which may also prevent the UA from normal operations in the terminal airspace. However, eliminating horizontal proximity (τmod) has the potential to increase “nuisance” alerts on the 45o entry and downwind legs. Overall, this suggests that a more stringent definition of Well Clear may be advisable in the landing pattern of the terminal area.

Trujillo, Anna C.↗
NASA NTRS1989

Development of a class of antennas for space-based Navstar GPS applications

This paper describes the performance of several unique antenna/ground plane configurations currently being developed for the TOPEX satellite and which may also be used for improved ground station operation. These antennas are designed with the objective of achieving nearly hemispherical coverage with sharp pattern cutoff above the horizon together with uniform phase response over the entire coverage area. The most promising of these designs is a uniform choke ring approximately 2 lambda in diameter. The ground planes, when used with the Dorne-Margolin C246 antenna element, produce smooth pattern cutoff of the order of 0.25 dB per deg over 135 deg, excellent LCP rejection, and rms phase deviation of 5-5.7 deg. Other ground plane designs, including larger choke ring structures, slotted ground planes, and the use of absorber material, proved much less effective.

Tranquilla, J. M.↗
NASA NTRS1991

A semi-automated process for the production of custom-made shoes

A more efficient, cost-effective and timely way of designing and manufacturing custom footware is needed. A potential solution to this problem lies in the use of computer-aided design and manufacturing (CAD/CAM) techniques in the production of custom shoes. A prototype computer-based system was developed, and the system is primarily a software entity which directs and controls a 3-D scanner, a lathe or milling machine, and a pattern-cutting machine to produce the shoe last and the components to be assembled into a shoe. The steps in this process are: (1) scan the surface of the foot to obtain a 3-D image; (2) thin the foot surface data and create a tiled wire model of the foot; (3) interactively modify the wire model of the foot to produce a model of the shoe last; (4) machine the last; (5) scan the surface of the last and verify that it correctly represents the last model; (6) design cutting patterns for shoe uppers; (7) cut uppers; (8) machine an inverse mold for the shoe innersole/sole combination; (9) mold the innersole/sole; and (10) assemble the shoe. For all its capabilities, this system still requires the direction and assistance of skilled operators, and shoemakers to assemble the shoes. Currently, the system is running on a SUN3/260 workstation with TAAC application accelerator. The software elements of the system are written in either Fortran or C and run under a UNIX operator system.

Farmer, Franklin H.↗
NASA NTRS2015

Modeling of an Adjustable Beam Solid State Light Project

This proposal is for the development of a computational model of a prototype variable beam light source using optical modeling software, Zemax Optics Studio. The variable beam light source would be designed to generate flood, spot, and directional beam patterns, while maintaining the same average power usage. The optical model would demonstrate the possibility of such a light source and its ability to address several issues: commonality of design, human task variability, and light source design process improvements. An adaptive lighting solution that utilizes the same electronics footprint and power constraints while addressing variability of lighting needed for the range of exploration tasks can save costs and allow for the development of common avionics for lighting controls.

Clark, Toni↗
NASA NTRS1988

Time-Zone-Pattern Satellite Broadcasting Antenna

Direct-broadcast satellite antenna designs provide contoured beams to match four time zones in 48 contiguous states and spot beams for Alaska, Hawaii, and Puerto Rico presented in 29-page report. Includes descriptions of procedures used to arrive at optimized designs. Arrangements, amplitudes, and phases of antenna feeds presented in tables. Gain contours shown graphically. Additional tables of performance data given for cities in service area of Eastern satellite.

Galindo, Victor↗
NASA NTRS2005

Reconfigurable Antennas for High Data Rate Multi-beam Communication Systems

High-speed (2-100 Mb/sec) wireless data communication - whether land- or satellite-based - faces a major challenge: high error rates caused by interference and unpredictable environments. A planar antenna system that can be reconfigured to respond to changing conditions has the potential to dramatically improve data throughput and system reliability. Moreover, new planar antenna designs that reduce array size, weight, and cost can have a significant impact on terrestrial and satellite communication system performance. This research developed new individually-reconfigurable planar antenna array elements that can be adjusted to provide multiple beams while providing increased scan angles and higher aperture efficiency than traditional diffraction-limited arrays. These new elements are microstrip spiral antennas with specialized tuning mechanisms that provide adjustable radiation patterns. We anticipate that these new elements can be used in both large and small arrays for inter-satellite communication as well as tracking of multiple mobile surface-based units. Our work has developed both theoretical descriptions as well as experimental prototypes of the antennas in both single element and array embodiments. The technical summary of the results of this work is divided into six sections: A. Cavity model for analysis and design of pattern reconfigurable antennas; B. Performance of antenna in array configurations for broadside and endfire operation; C. Performance of antenna in array configurations for beam scanning operation; D. Simulation of antennas in infinite phased arrays; E. Demonstration of antenna with commercially-available RF MEMS switches; F. Design of antenna MEMS switch combinations for direct simultaneous fabrication.

Bernhard, Jennifer T.↗
NASA NTRS1993

Spacesuit glove manufacturing enhancements through the use of advanced technologies

The sucess of astronauts performing extravehicular activity (EVA) on orbit is highly dependent upon the performance of their spacesuit gloves.A study has recently been conducted to advance the development and manufacture of spacesuit gloves. The process replaces the manual techniques of spacesuit glove manufacture by utilizing emerging technologies such as laser scanning, Computer Aided Design (CAD), computer generated two-dimensional patterns from three-dimensionl surfaces, rapid prototyping technology, and laser cutting of materials, to manufacture the new gloves. Results of the program indicate that the baseline process will not increase the cost of the gloves as compared to the existing styles, and in production, may reduce the cost of the gloves. perhaps the most important outcome of the Laserscan process is that greater accuracy and design control can be realized. Greater accuracy was achieved in the baseline anthropometric measurement and CAD data measurement which subsequently improved the design feature. This effectively enhances glove performance through better fit and comfort.

Cadogan, David↗
NASA NTRS2007

Hilbert-Curve Fractal Antenna With Radiation- Pattern Diversity

A printed, folded, Hilbert-curve fractal microwave antenna has been designed and built to offer advantages of compactness and low mass, relative to other antennas designed for the same operating frequencies. The primary feature of the antenna is that it offers the advantage of radiation-pattern diversity without need for electrical or mechanical switching: it can radiate simultaneously in an end-fire pattern at a frequency of 2.3 GHz (which is in the S-band) and in a broadside pattern at a frequency of 16.8 GHz (which is in the Ku-band). This radiation-pattern diversity could be utilized, for example, in applications in which there were requirements for both S-band ground-to-ground communications and Ku-band ground-to-aircraft or ground-to-spacecraft communications. The lack of switching mechanisms or circuitry makes this antenna more reliable, easier, and less expensive to fabricate than it otherwise would be.

Nessel, James A.↗
DOE OSTI2025

Thermal and Well Flow Performance of Closed-Loop Geothermal in the Wattenberg Area

Closed-loop geothermal systems provide an alternative to resource-constrained hydrothermal systems and stimulation-intensive enhanced geothermal systems. In this work, we apply the slender-body theory (SBT) model, to simulate the well flow and heat transfer performance of U-loop well designs in the Wattenberg area of the Denver-Julesburg Basin. Three U-loop well patterns are investigated, including a single-, double-, and multi-lateral design. The subsurface within the area of interest is characterized by deep, hot (> 200 degrees C) igneous/metamorphic basement rock underlying multiple sedimentary formations. The lateral section(s) of the U-loop lie(s) within a target depth of 6 km, where temperatures are estimated to approach 300 degrees C. As a base case, conduction-only heat transfer is investigated through simulations with the SBT model within U-loops with open-hole laterals that exchange heat directly with the hot, dry rock using water as a working fluid. The utilization of supercritical CO2 as a heat transfer fluid is also considered. For each scenario, the system performance in terms of annual heat production and temperature profile over a 20-year project lifetime are assessed. Also, the levelized costs of heat and electricity (LCOH and LCOE) are determined using a top-down techno-economic analysis model. The results show that the performance- and cost-optimized U-loop design is one having an injection-production well spacing of 1,000 meters with ten 50-meter-spaced laterals that traverse a subsurface system with a temperature gradient of 60 degrees C/km. By injecting 20 degrees C-water at a rate of 60 kg/s through this loop, an average heat production of 19 MWth (i.e., 2.2 MWe net plant output) can be achieved, resulting in an LCOE and LCOH of $136/MWhe and $1.53/GJ, respectively, over a 20-year project life.

closed-loop geothermal↗
NASA NTRS1991

Antenna pattern control using impedence surfaces

During this research period, September 16, 1990 to March 15, 1991, a design method for selecting a low-loss impedance material coating for a horn antenna pattern control has been developed. This method and the stepped waveguide technique can be employed to accurately compute the electromagnetic wave phenomenon inside the transition region of the horn antenna, with or without the impedance surfaces, from the feed to the radiating aperture. For moment method solutions of the electric and magnetic current distributions on the radiating aperture and the outer surface of the horn antenna, triangular surface-patch modes are introduced to replace the sinusoidal surface-patch modes as expansion and testing functions to provide a more physical expansion of the current distributions. In the synthesis problem, a numerical optimization process is formulated to minimize the error function between the desired waveguide modes and the modes provided by the horn transition with impedance surfaces. Since the modes generated by the horn transition with impedance surface are computed by analytical techniques, the computational error involved in the synthesis of the antenna pattern is minimum. Therefore, the instability problem can be avoided. A preliminary implementation of the techniques has demonstrated that the developed theory of the horn antenna pattern control using the impedance surfaces is realizable.

Balanis, Constantine A.↗
DOE OSTI2024

Hierarchical Composites Patterned via 3D Printed Cellular Fluidics

Additive manufacturing of freeform structures containing multiple materials with deterministic spatial arrangement and interactions remains a challenge for most 3D printing processes, due to complex fabrication tool requirements and limitations in printability of some material classes. Here, in this paper, a versatile method is reported to produce architected composites using the concept of cellular fluidics, in which lattices of unit cells are used as templating scaffolds to guide flowable infill materials in a programmed spatial pattern, upon which they are cured in place to produce a deterministically ordered multimaterial solid. The lattice design relies on the unit cell size, type, strut diameter, surface wetting, and distribution of cellular structures to control liquid flow and retention. Individual unit cells are tuned to achieve reliable infilling and combined into higher-order architectures to achieve multiscale composite materials with disparate mechanical properties, including those considered non-printable. Lattice design considerations for leveraging capillary phenomena and demonstrate several methods of patterning polymers in 3D-printed cellular fluidic structures are presented. The concept of tuning the compressive response of an architected composite using a flexible-elastomer as the lattice and a stiff-epoxy as the infill material is illustrated.

36 MATERIALS SCIENCE↗
NASA NTRS1993

Integrated reflector antenna design and analysis

Reflector antenna design is a mature field and most aspects were studied. However, of that most previous work is distinguished by the fact that it is narrow in scope, analyzing only a particular problem under certain conditions. Methods of analysis of this type are not useful for working on real-life problems since they can not handle the many and various types of perturbations of basic antenna design. The idea of an integrated design and analysis is proposed. By broadening the scope of the analysis, it becomes possible to deal with the intricacies attendant with modem reflector antenna design problems. The concept of integrated reflector antenna design is put forward. A number of electromagnetic problems related to reflector antenna design are investigated. Some of these show how tools for reflector antenna design are created. In particular, a method for estimating spillover loss for open-ended waveguide feeds is examined. The problem of calculating and optimizing beam efficiency (an important figure of merit in radiometry applications) is also solved. Other chapters deal with applications of this general analysis. The wide angle scan abilities of reflector antennas is examined and a design is proposed for the ATDRSS triband reflector antenna. The development of a general phased-array pattern computation program is discussed and how the concept of integrated design can be extended to other types of antennas is shown. The conclusions are contained in the final chapter.

Zimmerman, M. L.↗
DOE OSTI2024

Thermal and Well Flow Performance of Closed-Loop Geothermal in the Wattenberg Area: Preprint

Closed-loop geothermal systems provide an alternative to resource-constrained hydrothermal systems and stimulation-intensive enhanced geothermal systems. In this work, we apply the slender-body theory (SBT) model, to simulate the well flow and heat transfer performance of U-loop well designs drilled in the Wattenberg area of the Denver-Julesburg Basin. Three U-loop well patterns are investigated including a single, double, and multi-lateral design. The subsurface within area is characterized by deep, hot (> 200degreesC) igneous/metamorphic basement rock underlying multiple sedimentary formations. The lateral section(s) of the U-loop lies within a target depth of 6 km where temperatures are estimated to approach 300degreesC. As a base case, conduction-only heat transfer is investigated through simulations with the SBT model within U-loops with open-hole laterals that exchange heat directly with the hot dry rock using water as a working fluid. The utilization of supercritical CO2 as a heat transfer fluid is also considered. For each scenario, the system performance in terms of annual heat production and temperature profile over a 20-year project lifetime are assessed. Also, the levelized costs of heat and electricity (LCOH and LCOE) are determined using a top-down technoeconomic analysis model. The results show that the performance and cost optimized U-loop design is one having an injection-production well spacing of 1,000 meters with ten 50-meter-spaced laterals that traverse a subsurface system with a temperature gradient of 60degreesC/km. By injecting 20 degreesC-water at a rate of 60 kg/s through this loop, an average heat production of 19 MWth can be achieved, resulting in an LCOE and LCOH of $136/MWh and $1.53/GJ, respectively, over a 20-year project life.

closed-loop geothermal↗
NASA NTRS2014

Design, Analysis, and On-Sun Evaluation of Reflective Strips Under Controlled Buckling

Solar concentrators are envisioned for use in a variety of space-based applications, including applications involving in situ resource utilization. Identifying solar concentrators that minimize mass and cost are of great interest, especially since launch cost is driven in part by the mass of the payload. Concentrators must also be able to survive the wide temperature excursions on the lunar surface. Identifying smart structures which compensate for changes in concentrator geometry brought about by temperature extremes are of interest. Some applications may benefit from the ability to change the concentrators focal pattern at will. This paper addresses a method of designing a single reflective strip to produce a desired focal pattern through the use of controlled buckling. Small variations in the cross section over the length of the reflective strip influence the distribution of light in the focal region. A finite element method of analysis is utilized here which calculates the curve produced for a given strip cross section and axial load. Varying axial force and strip cross section over the length of the reflective strip provide a means of optimizing ray convergence in the focal region. Careful selection of a tapered cross section yields a reflective strip that approximates a parabola. An array of reflective strips under controlled buckling produces a light weight concentrator and adjustments in the compression of individual strips provide a means of compensating for temperature excursions or changing the focal pattern at will.

solar collectors↗
DOE OSTI2025

Tactical Analysis for Calculating Contextual Risk at Boundaries: Summary of Laboratory Directed Research & Development Effort

The Tactical Analysis for Calculating Contextual Risk at Boundaries (TACCRAB) tool is an innovative digital twin (DT) platform and automated risk algorithm designed to transform operational decision-making in structured screening environments, with an initial focus on Southern Border Land Ports of Entry (POEs). The invention provides integration points for advanced artificial intelligence, predictive modeling, and real-time data analysis to produce a comprehensive risk management tool that enables proactive, data-informed security strategies. The core inventive features of TACCRAB center on its unique risk algorithm, which dynamically calculates contextual risk by synthesizing historical data, near real-time streaming data from the checkpoints themselves, and AI-generated predictions. Unlike traditional risk assessment methods, TACCRAB utilizes a DT to provide comprehensive operational insights, allowing stakeholders to visualize, simulate, and optimize checkpoint configurations with unprecedented speed and contextual awareness. TACCRAB's key innovation lies in its ability to combine multiple complex inputs - including technology detection probabilities, resource availability, screening pathway characteristics, and threat actor behavioral patterns - into a unified risk calculation and update these inputs based on changing operational and environmental conditions. By leveraging a DT that continuously updates and learns from linked data, TACCRAB can suggest adaptive mitigation strategies that minimize risk while maintaining operational efficiency. Particularly novel is the platform's approach to decision support, which goes beyond static risk assessment. The DT provides dynamic metrics such as wait times, resource allocation effectiveness, and potential emerging threat scenarios, enabling users to view sophisticated, relevant what-if simulations and optimize checkpoint operations in near real-time. The system's architecture allows for generalized application across different screening environments, such as secure facilities, ports of entry, and soft targets, making it a versatile tool for security and operational management. The invention distinguishes itself through its comprehensive integration of predictive modeling, AI-driven pattern discovery, and user-friendly interface design. By combining these elements, TACCRAB transforms complex risk data into actionable insights, supporting decision-makers at various organizational levels - from booth agents making split-second screening decisions to checkpoint managers optimizing the day's resource allocation to strategic planners managing long-term investments.

45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEF↗
NASA NTRS2014

Design, Analysis, and On-Sun Evaluation of Reflective Strips Under Controlled Buckling

Solar concentrators are envisioned for use in a variety of space-based applications, including applications involving in situ resource utilization. Identifying solar concentrators that minimize mass and cost are of great interest, especially since launch cost is driven in part by the mass of the payload. Concentrators must also be able to survive the wide temperature excursions on the lunar surface. Identifying smart structures which compensate for changes in concentrator geometry brought about by temperature extremes are of interest. Some applications may benefit from the ability to change the concentrator's focal pattern at will. This paper addresses a method of designing a single reflective strip to produce a desired focal pattern through the use of controlled buckling. Small variations in the cross section over the length of the reflective strip influence the distribution of light in the focal region. A finite element method of analysis is utilized here which calculates the curve produced for a given strip cross section and axial load. Varying axial force and strip cross section over the length of the reflective strip provide a means of optimizing ray convergence in the focal region. Careful selection of a tapered cross section yields a reflective strip that approximates a parabola. An array of reflective strips under controlled buckling produces a light weight concentrator and adjustments in the compression of individual strips provide a means of compensating for temperature excursions or changing the focal pattern at will.

buckling↗
NASA NTRS1991

Cross-Quint-Bridge Resistor

Integrated-circuit conductive test pattern intended to provide data on effects of design widths and design spacings upon actual widths of conductive lines. Provides for electrical measurements both on lines of unknown width and on features having known dimensions. Data from measurements on five bridges used to determine four parameters of mathematical model describing system. In principle, pattern determines effects of width and spacing and interaction between them.

Hannaman, David J.↗
NASA NTRS2008

Column Grid Array Rework for High Reliability

Due to requirements for reduced size and weight, use of grid array packages in space applications has become common place. To meet the requirement of high reliability and high number of I/Os, ceramic column grid array packages (CCGA) were selected for major electronic components used in next MARS Rover mission (specifically high density Field Programmable Gate Arrays). ABSTRACT The probability of removal and replacement of these devices on the actual flight printed wiring board assemblies is deemed to be very high because of last minute discoveries in final test which will dictate changes in the firmware. The questions and challenges presented to the manufacturing organizations engaged in the production of high reliability electronic assemblies are, Is the reliability of the PWBA adversely affected by rework (removal and replacement) of the CGA package? and How many times can we rework the same board without destroying a pad or degrading the lifetime of the assembly? To answer these questions, the most complex printed wiring board assembly used by the project was chosen to be used as the test vehicle, the PWB was modified to provide a daisy chain pattern, and a number of bare PWB s were acquired to this modified design. Non-functional 624 pin CGA packages with internal daisy chained matching the pattern on the PWB were procured. The combination of the modified PWB and the daisy chained packages enables continuity measurements of every soldered contact during subsequent testing and thermal cycling. Several test vehicles boards were assembled, reworked and then thermal cycled to assess the reliability of the solder joints and board material including pads and traces near the CGA. The details of rework process and results of thermal cycling are presented in this paper.

high reliability↗