scholarly journals Preliminary Analysis of Solar Cell Interconnections Welding Parameters Using Design of Experiments for Future Optimization

2020 ◽  
pp. 12-24
Author(s):  
Graziela Fernanda de Souza Maia ◽  
Marcelo Lopes de Oliveira e Souza ◽  
Alírio Cavalcanti de Brito
Keyword(s):  
Solar Cells ◽  
Design Of Experiments ◽  
Preliminary Analysis ◽  
Welding Process ◽  
Welding Parameters ◽  
Solar Panels ◽  
Space Applications ◽  
Analysis And Design ◽  
And Performance ◽  
Big Cell

One of the processes that determine the reliability of solar panels used in space applications is the welding of interconnections between two adjacent solar cells. This process has various technologies, sequences and activities that have various characteristics, factors and parameters. Their combinations and values allow countless possibilities, making their adjustments time consuming, costly and exhausting. One way of abbreviating this, achieving competitiveness and meeting the needs of stakeholders is through the Analysis and Design of Experiments. This technique helps in optimizing the best adjustments to obtain the expected results. Thus, this paper presents a preliminary analysis of the parameters and their interactions of the welding process (by parallel-gap resistance welding) of interconnections between solar cells using design of experiments. In this welding process, the cell undergoes a certain level of degradation. For this reason, it is important to determine which process parameters are important and their proper levels, without big cell degradation. The result of this analysis can be used in the future to optimize the welding process meeting the design requirements for reliability and performance.

scholarly journals Optimization of Friction Welding Process Parameters for 42Cr9Si2 Hollow Head and Sodium Filled Engine Valve and Valve Performance Evaluation

Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1123
Author(s):  
Fuqiang Lai ◽  
Shengguan Qu ◽  
Roger Lewis ◽  
Tom Slatter ◽  
Ge Sun ◽  
...  
Keyword(s):  
Performance Evaluation ◽  
Friction Welding ◽  
Elevated Temperatures ◽  
Welding Process ◽  
Process Parameter ◽  
Superior Performance ◽  
Welding Parameters ◽  
Manufacturing Method ◽  
Rotating Bending Fatigue ◽  
And Performance

Due to their design, hollow cavity and filled sodium, hollow head and sodium filled engine valves (HHSVs) have superior performance to traditional solid valves in terms of mass and temperature reduction. This paper presents a new manufacturing method for 42Cr9Si2 steel hollow head and sodium filled valves. An inertia friction welding process parameter optimization was conducted to obtain a suitable process parameter range. The fatigue strength of 42Cr9Si2 steel at elevated temperatures was evaluated by rotating bending fatigue test with material specimens. Performance evaluation tests for real valve components were then carried out using a bespoke bench-top apparatus, as well as a stress evaluation utilizing a finite element method. It was proved that the optimized friction welding parameters of HHSV can achieve good welding quality and performance, and the HHSV specimen successfully survived defined durability tests proving the viability of this new method. The wear resistance of the HHSV specimens was evaluated and the corresponding wear mechanisms were found to be those classically defined in automotive valve wear.

Optimization of Parameters for CO2-Gas Shielding Arc Welding Based on the Double Weights Neural Network

2011 ◽  
Vol 304 ◽  
pp. 175-179
Author(s):  
Lin Lin Lv ◽  
Ju Ping Gu ◽  
Liang Hua ◽  
Wei Fan ◽  
Yu Jian Qiang
Keyword(s):  
Neural Network ◽  
Arc Welding ◽  
Welding Process ◽  
Welding Parameters ◽  
Bp Network ◽  
Optimization Of Parameters ◽  
Highly Nonlinear ◽  
Scale Experiment ◽  
And Performance ◽  
Process Detection

It is very difficult to predict the process detection and performance parameters, because of the highly nonlinear and multivariable coupling of welding process. In this paper, we construct a new method in optimization of parameters for CO2-gas shielding arc welding. By using the new Double Weights Model, this algorithm can give the Direction Weight, also the Core Weight at the same time. The new network inherits the traditional BP network and RBF (Radial Basis Functions) network with multivariable parameter settings and so on. We apply the network to the optimization of welding parameters, experimental results show that this algorithm can use less generations to calculate and get more accurate optimization effects, also not serious about a local minimum compared with RBF while using the same environment and equal network scale. Experiment proves that it is feasible to control welding parameters by the Double Weights Neural Network.

scholarly journals A Virtual Design of Experiments Method to Evaluate the Effect of Design and Welding Parameters on Weld Quality in Aerospace Applications

Aerospace ◽  
2019 ◽  
Vol 6 (6) ◽  
pp. 74 ◽  
Author(s):  
Julia Madrid ◽  
Samuel Lorin ◽  
Rikard Söderberg ◽  
Peter Hammersberg ◽  
Kristina Wärmefjord ◽  
...  
Keyword(s):  
Design Of Experiments ◽  
Welding Process ◽  
Source Model ◽  
Welding Parameter ◽  
Welding Parameters ◽  
Virtual Design ◽  
Welding Simulation ◽  
Aerospace Applications ◽  
Simulation Techniques ◽  
Short Time

During multidisciplinary design of welded aircraft components, designs are principally optimized upon component performance, employing well-established modelling and simulation techniques. On the contrary, because of the complexity of modelling welding process phenomena, much of the welding experimentation relies on physical testing, which means welding producibility aspects are considered after the design has already been established. In addition, welding optimization research mainly focuses on welding process parameters, overlooking the potential impact of product design. As a consequence, redesign loops and welding rework increases product cost. To solve these problems, in this article, a novel method that combines the benefits of design of experiments (DOE) techniques with welding simulation is presented. The aim of the virtual design of experiments method is to model and optimize the effect of design and welding parameters interactions early in the design process. The method is explained through a case study, in which weld bead penetration and distortion are quality responses to optimize. First, a small number of physical welds are conducted to develop and tune the welding simulation. From this activity, a new combined heat source model is presented. Thereafter, the DOE technique optimal design is employed to design an experimental matrix that enables the conjointly incorporation of design and welding parameters. Welding simulations are then run and a response function is obtained. With virtual experiments, a large number of design and welding parameter combinations can be tested in a short time. In conclusion, the creation of a meta-model allows for performing welding producibility optimization and robustness analyses during early design phases of aircraft components.

scholarly journals Review of State-of-the-Art Green Monopropellants: For Propulsion Systems Analysts and Designers

Aerospace ◽  
2021 ◽  
Vol 8 (1) ◽  
pp. 20
Author(s):  
Ahmed E. S. Nosseir ◽  
Angelo Cervone ◽  
Angelo Pasini
Keyword(s):  
Environmental Sustainability ◽  
Electric Propulsion ◽  
High Performance ◽  
Systems Design ◽  
Propulsion Systems ◽  
Space Applications ◽  
Analysis And Design ◽  
Research Activities ◽  
Systems Analysts ◽  
And Performance

Current research trends have advanced the use of “green propellants” on a wide scale for spacecraft in various space missions; mainly for environmental sustainability and safety concerns. Small satellites, particularly micro and nanosatellites, evolved from passive planetary-orbiting to being able to perform active orbital operations that may require high-thrust impulsive capabilities. Thus, onboard primary and auxiliary propulsion systems capable of performing such orbital operations are required. Novelty in primary propulsion systems design calls for specific attention to miniaturization, which can be achieved, along the above-mentioned orbital transfer capabilities, by utilizing green monopropellants due to their relative high performance together with simplicity, and better storability when compared to gaseous and bi-propellants, especially for miniaturized systems. Owing to the ongoing rapid research activities in the green-propulsion field, it was necessary to extensively study and collect various data of green monopropellants properties and performance that would further assist analysts and designers in the research and development of liquid propulsion systems. This review traces the history and origins of green monopropellants and after intensive study of physicochemical properties of such propellants it was possible to classify green monopropellants to three main classes: Energetic Ionic Liquids (EILs), Liquid NOx Monopropellants, and Hydrogen Peroxide Aqueous Solutions (HPAS). Further, the tabulated data and performance comparisons will provide substantial assistance in using analysis tools—such as: Rocket Propulsion Analysis (RPA) and NASA CEA—for engineers and scientists dealing with chemical propulsion systems analysis and design. Some applications of green monopropellants were discussed through different propulsion systems configurations such as: multi-mode, dual mode, and combined chemical–electric propulsion. Although the in-space demonstrated EILs (i.e., AF-M315E and LMP-103S) are widely proposed and utilized in many space applications, the investigation transpired that NOx fuel blends possess the highest performance, while HPAS yield the lowest performance even compared to hydrazine.

Optimization of A-GTAW welding parameters for naval steel (DMR 249 A) by design of experiments approach

2015 ◽  
Vol 231 (3) ◽  
pp. 320-331 ◽  
Author(s):  
Rishi Pamnani ◽  
M Vasudevan ◽  
P Vasantharaja ◽  
T Jayakumar
Keyword(s):  
Design Of Experiments ◽  
Process Parameters ◽  
Arc Welding ◽  
Welding Process ◽  
Gas Tungsten Arc Welding ◽  
Welding Parameters ◽  
Single Pass ◽  
Gas Tungsten Arc ◽  
Gtaw Process ◽  
Gas Tungsten

DMR249A steel is indigenously developed high strength low alloy (HSLA) steel. The steel is being used for construction of Indian Aircraft Carrier and other new ships under construction at various ship yards in India. In order to enhance the depth of penetration (DOP) achievable in a single pass for gas tungsten arc welding (GTAW) process, activated fluxes were developed for the steel. The process is called activated flux gas tungsten arc welding (A-GTAW). Design of experiments (DOE) approach was employed using response surface methodology (RSM) and Taguchi technique to optimize the welding parameters for achieving maximum DOP in a single pass. Design matrix was generated using DOE techniques and bead on plate experiments were carried out to generate data for influence of welding process variables on DOP. The input variables considered were current, torch speed, and arc gap. The DOP was considered as response variable. The equations correlating DOP with the process parameters were developed for both the optimization techniques. The identified optimum process parameters were validated by carrying out bead on plate experiments. The RMS error of the predicted and measured DOP values for the validation experiments of the RSM (D-optimal) and Taguchi optimization technique was found to be 0.575 and 0.860, respectively. Thus, RSM (D-optimal) was observed to predict optimized welding process parameters for achieving maximum DOP with better accuracy during A-GTAW process.

scholarly journals Tunnel Junctions for III-V Multijunction Solar Cells Review

Crystals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 445 ◽  
Author(s):  
Peter Colter ◽  
Brandon Hagar ◽  
Salah Bedair
Keyword(s):  
Solar Cells ◽  
Tunnel Junction ◽  
Tunnel Junctions ◽  
Current Standard ◽  
Space Applications ◽  
Doped Semiconductors ◽  
Significant Performance ◽  
And Performance ◽  
Transparent Semiconductor ◽  
Performance Gains

Tunnel Junctions, as addressed in this review, are conductive, optically transparent semiconductor layers used to join different semiconductor materials in order to increase overall device efficiency. The first monolithic multi-junction solar cell was grown in 1980 at NCSU and utilized an AlGaAs/AlGaAs tunnel junction. In the last 4 decades both the development and analysis of tunnel junction structures and their application to multi-junction solar cells has resulted in significant performance gains. In this review we will first make note of significant studies of III-V tunnel junction materials and performance, then discuss their incorporation into cells and modeling of their characteristics. A Recent study implicating thermally activated compensation of highly doped semiconductors by native defects rather than dopant diffusion in tunnel junction thermal degradation will be discussed. AlGaAs/InGaP tunnel junctions, showing both high current capability and high transparency (high bandgap), are the current standard for space applications. Of significant note is a variant of this structure containing a quantum well interface showing the best performance to date. This has been studied by several groups and will be discussed at length in order to show a path to future improvements.

Effects of bottom plate in friction stir welding of AA6061-T6

2020 ◽  
Vol 118 (1) ◽  
pp. 108
Author(s):  
M.A. Vinayagamoorthi ◽  
M. Prince ◽  
S. Balasubramanian
Keyword(s):  
Mechanical Properties ◽  
Axial Load ◽  
Weld Zone ◽  
Welding Process ◽  
Bottom Plate ◽  
Welding Parameters ◽  
Nugget Zone ◽  
Friction Stir ◽  
Weld Joints ◽  
Fine Grain

The effects of 40 mm width bottom plates on the microstructural modifications and the mechanical properties of a 6 mm thick FSW AA6061-T6 joint have been investigated. The bottom plates are placed partially at the weld zone to absorb and dissipate heat during the welding process. An axial load of 5 to 7 kN, a rotational speed of 500 rpm, and a welding speed of 50 mm/min are employed as welding parameters. The size of the nugget zone (NZ) and heat-affected zone (HAZ) in the weld joints obtained from AISI 1040 steel bottom plate is more significant than that of weld joints obtained using copper bottom plate due to lower thermal conductivity of steel. Also, the weld joints obtained using copper bottom plate have fine grain microstructure due to the dynamic recrystallization. The friction stir welded joints obtained with copper bottom plate have exhibited higher ductility of 8.9% and higher tensile strength of 172 MPa as compared to the joints obtained using a steel bottom plate.

MANUFACTURING OF ENERGY EFFICIENT SOLAR PANELS

2020 ◽  
Author(s):  
Андрей Дмитриевич Бухтеев ◽  
Виктория Буянтуевна Бальжиева ◽  
Анна Романовна Тарасова ◽  
Фидан Гасанова ◽  
Светлана Викторовна Агасиева
Keyword(s):  
Energy Efficiency ◽  
Solar Cells ◽  
Energy Efficient ◽  
Solar Panels

В данном обзоре приведены проблемы при использовании солнечных элементов и существующие решения этих проблем по повышению энергоэффективности фотоэлементов. Также сравнивается КПД этих солнечных элементов и рассматриваются их особенности. Одним из самых эффективных способов стало применение нанотехнологий. This review presents the problems of using solar cells and existing solutions to these problems to improve the energy efficiency of solar cells. The efficiency of these solar cells is also compared and their features are considered. One of the most effective methods was the use of nanotechnology.

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