In this paper, based on factorial design of experiments method (DoE), predictive model and surface response analysis methodology was used for studying, modeling, characterizing and optimizing the ...parameters of a mono-crystalline photovoltaic (PV) panel behavior considering the interactive effects of two variables surface PV cell temperature and solar irradiation levels. The DoE concept allows finding the predictive model of each parameter behavior that uses the experimental data. It enables accurate predictions of the responses according to input factors variations. This contribution evaluates the output parameters by predicting these mathematical models of the three responses of a mono-crystalline PV panel: the maximum power , the short-circuit current and the open circuit voltage as function of the influences of both input parameter factors: illumination and temperature. In addition, to validate the results of the DoE predictive models, the surface response and the contour curves analysis were used to bring out the optimum of each response in each operating point covering the domain of the study by the use of a script developed under Minitab is deduced. The obtain results are compared with experimental data.
This article is focused on the prediction model of surface roughness parameters of structural steel created by plasma arc cutting. Optimization of the cutting process is very important from both ...quality and economy point of view. The presented paper shows the carrying out of the experiment with the specification of the design of experiments method. In these experiments, the influence of three factors ‐ the plasma current, the traverse speed, and plasma gas pressure was observed. Experimental material was selected structural steel S355. Along with the influence of controllable process factors was observed the influence of different plasma gasses. Application of different plasma gas significantly changes surface quality. The result of each experiment series is a regression function that can predict the Rz values according to the process parameters at given intervals. Presented equations can be applied in the production process for adjusting the plasma cutting process in order to achieve required surface quality.
Membrane distillation (MD) is a promising technology to treat mine water. This work aims to investigate the change in mass and heat transfer in reverse osmosis mine water treatment by vacuum membrane ...distillation (VMD). A 3D computational fluid dynamics (CFD) model was carried out using COMSOL Multiphysics and verified by the experimental results. Then, response Surface Methodology (RSM) was used to explore the effects of various parameters on the permeate flux and heat transfer efficiency. In terms of the influence degree on the permeation flux, the vacuum pressure > feed temperature > membrane length > feed temperature membrane length, and the membrane length has a negative correlation with the membrane flux. Increasing the feed temperature can also increase the convective heat transfer at the feed side, which will affect the heat transfer efficiency. Furthermore, the feed temperature also has a critical effect on the temperature polarization phenomenon. The temperature polarization becomes more notable at high temperatures.
Stress concentration at the corner bends of an anti-roll bar that is designed for an intercity passenger bus is reduced by optimising the shape of the critical regions. In order to do this, ...parameters which constitute the geometry of the stress concentrated regions are determined. The effect of these parameters on stress concentration is evaluated by using Design of Experiments (DoE) approach. Possible design options and their corresponding mass and maximum equivalent stress values are obtained by using finite element analysis. The results are assessed by means of response surfaces generated by FEA software. Transition form that gives optimum stress concentration is determined.
Nowadays sector of a building is one of the biggest energy consuming field and ranked first in many countries. The energy consumption for the building is related to the design stage. Many factors ...that should be taken into account for this stage, such as techno-economical parameters, directly affect the building energy consumption. Co-simulation is applied to optimize the design of residential buildings located in a hot climate to minimize life cycle costs while increasing their energy efficiency. A new approach of building performance assessment based on parametric design and analysis life cycle cost used the co-simulation method, in this study, we reduced the need for seasonal energy consumption by air conditioners and analyzed life cycle cost, 15 thermal and geometric factors are selected in this study such as Surface, Factor form, heat transfer through the walls, roof, and ground, also coefficient of absorption for solar radiation of the roof and the wall, Windows to Wall Ration and Factor Solar of Windows for four directions North, South, East, and West. The results of the metamodel from the co-simulation are compared against those obtained from a TRNSYS dynamic simulation; the fractional factorial metamodel has been accurate results. Then, the optimal design features of the envelope building are determined with life cycle cost can be saved 30.21%.
Le bâtiment est considéré comme étant le premier secteur consommateur d’énergie dans le monde. Dans la région méditerranéenne, face à la crise économique et aux engagements pris pour limiter les ...effets produisant le réchauffement climatique, il est devenu impératif de réduire la consommation énergétique des bâtiments que ce soit par la conception des bâtiments neufs ou par la réhabilitation du parc existant. Dans ce cadre-là, chercher des solutions techniques optimales en tenant compte des critères économiques, environnementaux et sociétaux est un problème très complexe du fait du nombre élevé de paramètres à prendre en compte. Pour remédier à ce problème, un état de l’art des méthodes d’optimisation multicritère a été réalisé. Nous avons constaté que plusieurs contraintes existent lors de l’utilisation de ces méthodes telles qu’un temps de calcul élevé et la non-maîtrise de la convergence des résultats vers des optimums globaux recherchés. L’objectif de notre travail est de proposer une nouvelle méthode qui permette de contourner ces difficultés. Cette méthode est basée, dans un premier temps, sur le développement des modèles polynomiaux pour la prédiction des besoins de chauffage, de refroidissement, d’énergie finale et du confort thermique d’été à l’aide du logiciel TRNSYS. Pour établir ces modèles, nous avons utilisé la méthode des plans d’expériences et des simulations thermiques dynamiques. À partir de ces modèles, une analyse de sensibilité a été entamée afin d’identifier les paramètres les plus influents sur les besoins énergétiques et le confort thermique d’été. Une base de données est utilisée associant chaque paramètre à son coût et à son impact environnemental sur son cycle de vie. Ensuite, une étude paramétrique complète a été réalisée en utilisant les fonctions polynomiales dans le but de déterminer un ensemble de solutions optimales à l’aide de l’approche du Front de Pareto. Cette nouvelle méthode a été appliquée dans le but de concevoir des bâtiments neufs à haute efficacité énergétique à des coûts maîtrisés pour les six zones climatiques du Maroc. La validation des modèles polynomiaux réalisée grâce à une comparaison avec des simulations aléatoires a donné des résultats très satisfaisants. Avec un modèle polynomial de second degré, l’erreur maximale sur les besoins énergétiques et le confort thermique adaptatif d’été ne dépasse pas 2 kWh/m².an et 9% respectivement dans la plupart des cas. Les modèles développés ont ensuite été utilisés pour l’aide à la décision multicritères. Les résultats obtenus ont montré que des bâtiments à très faibles besoins énergétiques peuvent être construits à un coût raisonnable, et qu’un effort doit être porté sur des solutions plus performantes pour le rafraîchissement en été. Enfin, nous avons mis en œuvre la méthode que nous avons développée dans le cadre de la réhabilitation d’un bâtiment existant à La Rochelle. Les critères environnementaux ont aussi été intégrés à la recherche de solutions optimales. La solution retenue selon 14 critères correspond à un ensemble de solutions techniques permettant d’obtenir des besoins de chauffage de l’ordre de 15 kWh/m².an avec un compromis réalisé entre l’efficacité énergétique, le confort des occupants, les impacts environnementaux et la maîtrise du coût de la réhabilitation. La méthode développée dans le cadre de ce travail a montré un fort potentiel d’utilisation pour l’aide à la décision multicritère lors de la conception des bâtiments neufs ou en réhabilitation. Elle permet d’effectuer très rapidement une optimisation opérationnelle de l’enveloppe pour contribuer à des bâtiments durables, confortables, à coût maîtrisé et à basse consommation énergétique.
The building sector is the largest consumer of energy in the world. In Mediterranean region, facing the economic crisis and commitments for climate change, the reduction of energy consumption for both new and existing buildings is more necessary. Against this background, seeking optimal technical solutions taking into account the economic, environmental and societal criteria is a very complex problem due to the high number of parameters to consider. In order to solve this problem, a state of the art of multi-criteria optimization method has been achieved. We found that many constraints exist when using these methods such as high time calculation and no absolute assurance to find the global optimum. Thus, the main objective of the present work is to propose a new method that allows overcome these difficulties. This method is based on the development of polynomial models for the prediction of heating energy needs, cooling energy needs, final energy needs and summer thermal comfort. To establish these models, we used the design of experiments method and dynamic thermal simulations using TRNSYS software. From these models, a sensitivity analysis has been achieved in order to identify the leading parameters on energy requirements and thermal comfort in summer. A database associating each parameter for its cost and environmental impact on its lifetime was generated from CYPE software and INIES database. Then, a detailed parametric study was performed using polynomial functions for determining a set of optimal solutions using the Pareto front approach. This new method was applied to design new buildings with high energy efficiency at controlled costs for the six Moroccan climate zones. The validation of polynomial models through a comparison with random simulations gave very satisfactory results. With a polynomial model of the second order, the maximum error on the energy needs and the adaptive thermal comfort did not exceed 2 kWh/m².an and 9% respectively. The developed models were used for multiple-criteria decision analysis. The results showed that buildings with very low energy needs can be built with a reasonable cost. On the other hand an effort should be focused on more efficient solutions for adaptive thermal comfort in summer especially for Marrakech and Errachidia. Finally, we also implemented our method to a project of energy rehabilitation of an existing building located in La Rochelle (France). Environmental criteria were also taken into account in the optimization process. The selected technical solutions procured approximately 15 kWh/m².year of heating energy needs. The developed multicriteria decision method showed a great potential for both designing new and existing buildings with high energy efficiency. It allows a very fast operational optimization of sustainable buildings at reasonable cost and low energy consumption.
Nowadays, wave energy exploitation is of great interests due to its sustainability, reliability and large potential. This paper aims to improve the rotor blade performances especially the efficiency ...of a self-rectifying impulse radial turbine which is in use in OWC devices. Symmetrical blade profile based on use of circular arcs and straight lines has been adopted. A new procedure for optimizing the geometrical blade parameters has been implemented in this work. The Design of Experiments (DOE) method has been adopted with 4 blade geometrical parameters and 2 levels for optimizing the number of numerical tests to determine the optimal profile equilibrating the efficiency between exhalation and inhalation modes. Numerical simulations in the whole turbine geometry have been carried out with ANSYS FLUENT for efficiency computation. Significant differences in this parameter have been noticed by varying the rotor blade profile. Optimal rotor geometry in both modes is obtained with a maximum efficiency of about 70 %.
Design of a Non-contact Electromagnetic Impact Mechanism HOSOKAWA, Hiroyuki; HIRATA, Katsuhiro; NIGUCHI, Noboru ...
Journal of the Japan Society of Applied Electromagnetics and Mechanics,
2013, Volume:
21, Issue:
3
Journal Article
Open access
We have proposed a non-contact electromagnetic impact-torque mechanism (EMI mechanism) using induced current, and its characteristics have been verified by using 3-D finite element method (FEM) ...analysis and carrying out measurements on a prototype. This paper describes an optimization method of the parameters of the electromagnetic impact system - such as dimension and number of poles - using the Design of Experiments (DOE) method. From this result, we can obtain a design guide for constructing an efficient EMI mechanism by using the DOE method.
This study is a part of an effort to develop precision injection molding of LCP. With the objection of replacing die-casted aluminum with injection molded LCP in an HDD actuator E-block application, ...modified design of experiment methods were used to investigate the significant factors involved both the injection machine operation process and the mold design. The preciseness was defined by the standard deviation (σ) of the arm tip heights of the E-block as measured on a laser scan micrometer, and values were compared with that of the die-casted aluminum E-block used in the HDD market. Among the machine process factors cut-off pressure was the most important one. Among the mold factors a cavity having a one-point gate located behind the carriage portion and a bridge connecting three arm tips, which functions as a slug-well and provides distortion resistance, gave the highest precision. For the purposes of high precision the mold geometry should permit molten LCP to flow with high symmetry. The value of the σ under the optimized process gave equal or better than that of aluminum E-block.
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