SEARCH · Engineering Papers

Results for “Module manufacturing,”

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.

SourceResearch connectionFrom yearThrough year

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

At least 487 records · Page 27

All sources NASA NTRS DOE OSTI

DOE OSTI2019

Heterobarrier Varactors with Nonuniformly Doped Modulation Layers

Optimum shape of the capacitance–voltage (C–V) characteristic is a critical parameter determining the efficiency of frequency multiplication in heterobarrier varactors (HBVs) operating in the millimeter and submillimeter frequency ranges. A numerical model for calculating the C–V characteristics and leakage currents of HBV heterostructures with arbitrary composition and doping profiles has been verified on the basis of published and original experimental data. A specially designed HBV heterostructure with three undoped InAlAs/AlAs/InAlAs barriers surrounded by nonuniformly doped n-InGaAs modulation layers has been grown by molecular beam epitaxy on InP substrate. Prototype HBVs manufactured using the proposed heterostructure demonstrated a nearly cosine shape of the C–V curve at bias voltages up to 2 V, increased overlap capacitance, and low leakage currents.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗

NASA NTRS1966

The manufacture of typical, biologically clean, planetary landing spacecraft to be sterilized.

Fabrication procedure for biologically clean planetary landing module for later sterilization

PLANETARY SPACECRAFT↗

DOE OSTI2024

Identification of Dynamic Force Coefficients for an Additively Manufactured Hermetic Squeeze Film Bearing Support Damper Utilizing a Pass-Through Channel

Abstract The following paper presents breakthrough experimental results for a new hermetic squeeze film damper (HSFD) concept that is integrally designed within an externally pressurized tilting-pad radial gas bearing support. The flexibly damped gas bearing module was designed for a 7.2″ (183 mm) diameter shaft and fabricated using direct metal laser melting (DMLM); also known as additive manufacturing. The bearing and HSFD were sized based on ongoing studies for oil-free supercritical carbon dioxide (sCO2) power turbines in the 8.5 MW–10 MW power range. The development of the new damper concept was motivated by past dynamic testing on HSFD, which generated frequency-dependent stiffness and damping force coefficients. In efforts to eliminate the frequency dependency, a new HSFD architecture was conceived that adds accumulator volumes and a pass-through channel to previously conceived HSFD flow network designs. The other motivation for the work is the need to develop a cost-effective and reliable oil-free bearing technology that is scalable to large power turbomachinery applications. There were several objectives for the following work. The first objective was to successfully design and fabricate a single piece bearing-damper using additive manufacturing, while dimensionally controlling critical design features. The paper discusses the manufacturing steps and shows cut-ups that reveal adequate clearance control capability with internal damper clearances. The second objective was to perform experimental testing with the new HSFD design in efforts to extract stiffness and damping coefficients for excitation frequencies within 20–160 Hz and peak vibration amplitudes between 0.25 mils (6.35 microns) to 1 mil (25.4 microns). The test results for a single HSFD bearing module indicated that the design modifications to the HSFD architecture were successful in eliminating nearly all the frequency dependencies for the stiffness force coefficient. The dynamic tests yielded a stiffness coefficient that varied between 112 klb/in. (19.6 MN/m) and 96 klb/in. (16.8 MN/m). The damping force coefficient however, exhibited relatively more variation with frequency with values residing between 175 lb-s/in. (31 kN-s/m) to 214 lb-s/in. (37 kN-s/m). Finally, the paper advances a three-dimensional fluid-structure interaction (FSI) model using transient finite element analysis (FEA) coupled to a computational fluid dynamics (CFD) model. The FSI analysis performed between 20 Hz and 80 Hz was used to predict the stiffness and damping of the HSFD using a quarter-section model of the damper. The FSI analysis was able to support test results by showing only a 6–7.4% change in the magnitude of force coefficients. Stiffness predictions agree reasonably well with experiments whereas damping is underpredicted.

Engineering↗

NASA NTRS2010

Manufacturing and Integration Status of the JWST OSIM Optical Simulator

OSIM is a full field, cryogenic, optical simulator of the James Webb Space Telescope (JWST) Optical Telescope Element (OTE). It provides simulated point source/star images for optical performance testing of the JWST Integrated Science Instrument Module (ISIM). OSIM is currently being assembled at the Goddard Space Flight Center (GSFC). In this paper, we describe the capabilities, design, manufacturing and integration status, and uses of the OSIM during the optical test program of ISIM and the Science Instruments. Where applicable, the ISIM tests are also described.

Sullivan, Joe↗

DOE OSTI2018

Correlation of Qualification and Accelerated Testing with Field Degradation

Qualification testing of solar photovoltaic (PV) modules per IEC 61215 standard encompasses a set of well-defined accelerated stress tests (irradiation, environmental, mechanical and electrical) with strict pass/fail criteria based on functionality/performance, electrical and mechanical safety, and visual requirements. The qualification testing does not identify all the possible reliability failures or durability issues witnessed in the actual field. However, it does identify the major/catastrophic design quality issues (infant mortality), which could occur early in a module’s field life. Unfortunately, in the industry, there is no consensus-based standard or protocol available to validate manufacturers’ warranty period claims based on the end-of-life wear-out failure mechanisms. Being able to predict the field degradation rates and lifetime using mode-specific accelerated tests on moderately field-aged modules, for example 10 years, for certain commonly occurring degradation modes would be a powerful contribution to all the stakeholders of the PV industry. There is a need to formulate guidelines to find the correlation of accelerated testing with field degradation for individual degradation modes observed in the field. Potential approaches to fulfill this need were experimented in this project and are presented in this report. Two of the most commonly seen degradation modes – encapsulant browning and solder bond thermomechanical fatigue – are addressed in this report through presenting the accelerated testing methods and physical modelling approaches. Two accelerated test methods (UV and thermal cycling) were designed to induce the wear-out mechanisms in the modules and not infant mortality failures. To focus on the wear-out failure modes, the tests were performed on field-aged modules, instead of fresh modules, with known degradation rates and degradation modes. The degradation rates were measured based on the degradation rates of individual cell parameters (short-circuit current, I sc and series resistance, R s ) instead of the degradation rate of maximum power (P max ) which cannot be used to study any specific/limited degradation mode as the P max degradation could be caused by many different degradation modes. The key characteristic parameter considered for encapsulant discoloration and solder bond degradation is I sc and R s , respectively. The developed physical models/equations relating the testing degradation data and field weather data were utilized to determine the acceleration factor (AF) and to predict the degradation rate for a specific degradation mode of PV modules installed in two different climates, Arizona (hot) and New York (cold). The predicted degradation rates for encapsulant browning and solder bond degradation have also been validated against the actual measured field degradation rates. UV testing cost reduction: To determine acceleration factor, single UV chamber was used for accelerated UV testing at three different temperatures simultaneously, instead of three chambers for three temperatures (or one chamber sequentially which is an extremely time-consuming approach). A passive heating approach was successfully used to achieve and maintain multiple temperatures in the accelerated UV chamber. Foam insulation boards of varying thicknesses were utilized to obtain three different temperatures for UV testing. However, these foam materials tend to disintegrate in the presence of moisture. To alleviate this problem, silicone heating blankets with temperature controls and humidifier can be used if the UV testing is to be performed under hot-humid conditions instead of conventional hot-dry conditions. Thermal cycling testing cost reduction: Single thermal cycling chamber was used for accelerated thermal cycling testing at three different upper temperatures simultaneously, instead of three chambers for three upper temperatures (or one chamber sequentially which is an extremely time-consuming approach). An active heating approach based on silicone heating blankets was successfully used to achieve and maintain multiple upper temperatures in the accelerated thermal cycling chamber. Such blankets provide stable temperature control and thereby more reliable and repeatable for replicate experiments.

14 SOLAR ENERGY↗

DOE OSTI2019

A General Approach for Lab‐to‐Manufacturing Translation on Flexible Organic Solar Cells

Abstract The blossoming of organic solar cells (OSCs) has triggered enormous commercial applications, due to their high‐efficiency, light weight, and flexibility. However, the lab‐to‐manufacturing translation of the praisable performance from lab‐scale devices to industrial‐scale modules is still the Achilles' heel of OSCs. In fact, it is urgent to explore the mechanism of morphological evolution in the bulk heterojunction (BHJ) with different coating/printing methods. Here, a general approach to upscale flexible organic photovoltaics to module scale without obvious efficiency loss is demonstrated. The shear impulse during the coating/printing process is first applied to control the morphology evolution of the BHJ layer for both fullerene and nonfullerene acceptor systems. A quantitative transformation factor of shear impulse between slot‐die printing and spin‐coating is detected. Compelling results of morphological evolution, molecular stacking, and coarse‐grained molecular simulation verify the validity of the impulse translation. Accordingly, the efficiency of flexible devices via slot‐die printing achieves 9.10% for PTB7‐Th:PC 71 BM and 9.77% for PBDB‐T:ITIC based on 1.04 cm 2 . Furthermore, 15 cm 2 flexible modules with effective efficiency up to 7.58% (PTB7‐Th:PC 71 BM) and 8.90% (PBDB‐T:ITIC) are demonstrated with satisfying mechanical flexibility and operating stability. More importantly, this work outlines the shear impulse translation for organic printing electronics.

Meng, Xiangchuan↗

DOE OSTI2021

Modeling the Nonlinear Rheology of Polymer Additive Manufacturing

This report summarizes molecular and continuum simulation studies focused on developing physics - based predictive models for the evolution of polymer molecular order during the nonlinear processing flows of additive manufacturing. Our molecular simulations of polymer elongation flows identified novel mechanisms of fluid dissipation for various polymer architectures that might be harnessed to enhance material processability. In order to predict the complex thermal and flow history of polymer realistic additive manufacturing processes, we have developed and deployed a high - performance mesh - free hydrodynamics module in Sandia's LAMMPS software. This module called RHEO – short for Reproducing Hydrodynamics and Elastic Objects – hybridizes an updated - Lagrange reproducing - kernel method for complex fluids with a bonded particle method (BPM) to capture solidification and solid objects in multiphase flows. In combination, our two methods allow rapid, multiscale characterization of the hydrodynamics and molecular evolution of polymers in realistic processing geometries.

36 MATERIALS SCIENCE↗

NASA NTRS1979

Automated aray assembly, phase 2

A manufacturing process suitable for the large-scale production of silicon solar array modules at a cost of less than $500/peak kW is described. Factors which control the efficiency of ion implanted silicon solar cells, screen-printed thick film metallization, spray-on antireflection coating process, and panel assembly are discussed. Conclusions regarding technological readiness or cost effectiveness of individual process steps are presented.

Daiello, R. V.↗

NASA NTRS1986

Mobile Remote Manipulator

Turret, roll arm, and trolley enhance manipulator dexterity. Remote manipulator moves on trolley base along structure. Roll-axis arm positions manipulator arm so it can extend end effector under structure. Yaw-axis rotation gives added reach to arm above structure. Designed for handling, inspecting, and maintaining modules of space station. Manipulators having such capabilities useful on Earth; robots in manufacturing, erection of large structures, or performing complicated tasks in hazardous locations.

Coryell, S.↗

NASA NTRS2005

Tributary Analysis Monitoring System

A monitoring system for a fleet of vehicles includes at least one data acquisition and analysis module (DAAM) mounted on each vehicle in the fleet, a control module on each vehicle in communication with each DAAM, and terminal module located remotely with respect to the vehicles in the fleet. Each DAAM collects/analyzes sensor data to generate analysis results that identify the state of a plurality of systems of the vehicle. Each vehicle's control module collects/analyzes the analysis results from each onboard DAAM to generate vehicle status results that identify potential sources of vehicle anomalies. The terminal module collects/analyzes the analysis results and vehicle status results transmitted from each control module from the fleet of vehicles to identify multiple occurrences of vehicle anomalies and multiple occurrences of those vehicle systems operating at a performance level that is unacceptable. Results of the terminal module's analysis are provided to organizations responsible for the operation, maintenance and manufacturing of the vehicles in the fleet as well as the plurality of systems used in the fleet.

Stanley E Woodard↗

NASA NTRSDate not supplied

Tessellation and Numerical Simulation of the in-Space Assembled Telescope (iSAT) Reflector

A novel tessellation method has been developed to allow the use of uniform truss modules to form curved or doubly curved surfaces. To illustrate the method, the structural support for the doubly curved in-Space Assembled Telescope primary reflector is developed. The method intentionally leaves gaps at the nodes between identical connecting modules; the gaps are relatively small, on the order of 0.5% of the lattice characteristic cell size. Uniquely shaped nodal connectors called multi-nuts are generated to fill in the nodal gaps and connect adjacent modules. With optimization techniques, the size of these nodal gaps can be minimized to thereby minimize the incurred structural efficiency losses. Finite element analyses of the primary reflector were performed, and the structural efficiency losses amounted to a natural frequency reduction of 5%. The benefits of having uniform truss modules outweigh the structural penalties as it will greatly simplify assembly and lower manufacturing costs.

Tessellation↗

NASA NTRSDate not supplied

Tessellation and Numerical Simulation of the in-Space Assembled Telescope (iSAT) Reflector

Tessellation↗

DOE OSTI2025

The AMACStar ASIC for the HL-LHC ATLAS ITk Strip detector: design, verification, testing, and quality assurance

For the high-luminosity upgrade to the LHC (HL-LHC), the ATLAS detector at CERN requires an all-new inner detector, the Inner Tracker (ITk). The ITk Strip subdetector is made up of silicon modules, which include three types of radiation-hard ASICs. One of these is the Autonomous Monitor and Control (AMAC). The AMAC is manufactured by Global Foundries using 130 nm CMOS8RF DM technology and is approximately 3 by 5 mm in size. This ASIC autonomously monitors the temperatures, voltages, and currents in the module components while controlling critical values in order to prevent these quantities from reaching dangerous levels. The final design, AMACStar, was verified, tested, and ensured to perform all necessary functions. A quality control procedure using an in-house probe station set-up was developed in order to ensure that every individual chip on each wafer of AMACStars required by the ITk Strip project met performance requirements. The average per wafer yield of usable AMACStars is 92.33%, exceeding the design-specific 90% yield estimated for project costing. This estimate was based on actual yields for similar designs in this process.

Analogue electronic circuits↗

DOE OSTI2015

Life Cycle Assessment of Future Photovoltaic Electricity Production from Residential-scale Systems Operated in Europe

The photovoltaics (PV) industry is growing rapidly to meet the increasing demand of green power. As the industry grows, the manufacturing processes and the material and energy efficiencies of PV cells and panels are improving. To assess the impacts of this trend, future scenarios of single-crystalline (single-Si, also known as mono-crystalline) silicon and cadmium-telluride (CdTe) PV systems installed on European residences were established. Assessment of the improvement potential of PV electricity-generating technologies such as single-Si and CdTe could be considered in long-term energy strategy decisions. This study aims to provide scenario-based information about the environmental per-formance of single-Si and CdTe PV modules produced and operated in the far future (2030 to 2050). The deployment application assessed considers European residential roofs. We made scenario-dependent projections of key parameters for single-Si and CdTe PV panels manufactured in 2050. The parameters included cell efficiency, module efficiency, wafer thickness, cutting losses, kerf losses, silver use, glass thickness and operational lifetime. This study combines developments for these parameters with projections of the environmental performance of electricity mixes in the main manufacturing countries/regions (European Union, China and the United States of America) and with projections of the environ-mental performance of basic material production (aluminium, copper, magnesium, nickel, pig iron, zinc, clinker and flat glass) in the far future. The three scenarios used in the assessment of future PV electricity were categorized into three classes: 'business as usual' (BAU), 'realistic improvement' (REAL) and 'optimistic improvement' (OPT). It estimates the current life cycle greenhouse gas emissions of single-Si PV electricity produced on the roofs of European residences to be approximately 80 grams CO2-equi-valent per kWh (g CO2-eq per kWh). Based on the projected changes to key parameters and the background system, life cycle greenhouse gas (GHG) emissions could be reduced to 65% (scenario BAU), 31% (scenario REAL) and 18% (scenario OPT) of that value in the far future. Results for other life cycle assessment (LCA) metrics are also assessed in this study such as: non-renewable cumulative energy demand, acidification potential, human toxicity potential, photochemical ozone creation potential, particulate matter formation potential, and land use. We calculated the total energy payback time (EPBT) and the non-renewable energy payback time (NREPBT) in the far future of single-crystalline silicon-based PV panels operated in Europe by dividing the estimate of non-renewable cumulative energy demand of PV electricity for the given scenario by the non-renewable cumulative energy demand of the scenario-dependent national and regional non-renewable residual electricity mixes. The study estimates the payback time could be reduced from 2.4 years today to 1.7, 1.2 and 1.2 years (scenarios BAU, REAL and OPT, respectively) in the far future, based on the assumptions and projections in the analysis. It finally estimates the current life cycle greenhouse gas emissions of CdTe PV electricity produced on the roofs of European residences to be approximately 30 g CO2-eq per kWh. Based on the projected changes to key parameters and the background system, life cycle GHG emissions could be reduced to 70% (scenario BAU), 44% (scenario REAL) and 32% (scenario OPT) of that value in the far future.

14 SOLAR ENERGY↗

NASA NTRS2012

Grain Refinement of Freeform Fabricated Ti-6Al-4V Alloy Using Beam/Arc Modulation

Grain refinement can significantly improve the mechanical properties of freeform-fabricated Ti-6Al-4V alloy, promoting increased strength and enhanced isotropy compared with coarser grained material. Large beta-grains can lead to a segregated microstructure, in regard to both alpha-phase morphology and alpha-lath orientation. Beam modulation, which has been used in conventional fusion welding to promote grain refinement, is explored in this study for use in additive manufacturing processes including electron beam freeform fabrication (EBF(sup 3)) and gas-tungsten arc (GTA) deposition to alter solidification behavior and produce a refined microstructure. The dynamic molten pool size induced by beam modulation causes rapid heat flow variance and results in a more competitive grain growth environment, reducing grain size. Consequently, improved isotropy and strength can be achieved with relatively small adjustments to deposition parameters.

Mitzner, Scott↗

DOE OSTI2020

Improving Heat Conduction of Insulated Metal Substrate with Thermal Pyrolytic Graphite Core for SiC Power Module Packaging

TPG-core IMS concept was jointly explored in this study. Integrating high thermally conductive TPG graphite core into IMS is expected to simultaneously achieve high thermal conductivity from TPG and electrical functionalities from IMS. Nearly 2x thermal conductivity and 30% weight saving was demonstrated on TPG-core IMS compared to conventional Cu-core IMS. Significant junction temperature reduction (11°C) in steady state and power cycling was revealed by the thermal analysis as the result of improved thermal spreading in plane and through the thickness. The study also proved the manufacturability and compatibility of this TPG-core IMS structure to the existing IMS production and power module assembling. Finally, the integration of TPG and IMS paves a new packaging route to increase heat load, improve reliability, simplify module design and reduce assembling cost and number of steps.

36 MATERIALS SCIENCE↗

NASA NTRS1984

An improved logarithmic amplifier circuit for PDS microdensitometers

A high speed logarithmic amplifier circuit for the Perkin-Elmer PDS microdensitometer is discussed. The circuit is designed around an Analog Devices 757p log-amp module. The amplifier produces undistorted profiles of rapidly changing, dense ( 4) images over the available range of scanning speeds. The circuit board was designed to replace directly the manufacturer supplied unit; neither electrical nor mechanical modifications of the basic PDS are required. The performance of the circuit is illustrated through its effects on the overall modulation transfer function of the instrument and by scans of a well exposed stellar image. Circuit diagrams and parts lists a mechanism for obtaining either circuit board layout art work or finished circuit boards are presented.

Anderson, C. M.↗

NASA NTRS1975

Apollo Program Summary Report: Synopsis of the Apollo Program Activities and Technology for Lunar Exploration

Overall program activities and the technology developed to accomplish lunar exploration are discussed. A summary of the flights conducted over an 11-year period is presented along with specific aspects of the overall program, including lunar science, vehicle development and performance, lunar module development program, spacecraft development testing, flight crew summary, mission operations, biomedical data, spacecraft manufacturing and testing, launch site facilities, equipment, and prelaunch operations, and the lunar receiving laboratory. Appendixes provide data on each of the Apollo missions, mission type designations, spacecraft weights, records achieved by Apollo crewmen, vehicle histories, and a listing of anomalous hardware conditions noted during each flight beginning with Apollo 4.

Source record↗