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LES of rotating film-cooling performance in a 1-1/2 turbine stage

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Propulsion and Power Research 2019年第2期8卷 85-107页

作者： Nabeel Al-Zurfi Adel nasser Mechanical Engineering Department Faculty of EngineeringUniversity of KufaNajafIraq School of Mechanical Aerospace and Civil EngineeringThe University of ManchesterManchesterM139PLUK

The large eddy simulation method was employed to investigate the film-cooling performance in a low-speed rotor blade of a 1-1/2 turbine *** rotor blade height and axial chord length were 99 mm and 124.3 mm,*** rows of film holes were placed on the rotor blade surface,one each on the pressure and suction *** row had three cylindrical film holes with a diameter of 4 mm and a tangential injection angle of 28°on the pressure side and 361 on the suction *** Reynolds number was fixed at Re=1.92×10^(5)and the coolant-to-mainstream density ratio(DR)was about *** were carried out for three different rotating speeds of 1800,2100,and 2400 rpm with the blowing ratio(BR)varying from 0.3 to *** commercial CFD code STAR-CCM+was used to run the simulations using the WALE subgrid-scale model for modelling the *** results show that on the pressure side,the film coverage and filmcooling effectiveness decrease with increasing rotation number(Ro)and increase with increasing blowing ratio(BR).A higher Ro and lower BR result in a stronger film *** film injection with higher BR produces better film *** film deflects centrifugally where the deflection becomes greater with increasing *** the suction side,the film coverage and film-cooling effectiveness increase with increasing either Ro or BR and a centripetal deflection of the film is *** deflection of the film path could be amplified by either increasing the Ro at a constant BR or decreasing the BR at a constant *** the rotation weakens the film deflection towards the hub on the suction ***,it was found that both rotation number and blowing ratio play significant roles in determining the film-cooling effectiveness distributions of the rotor blade surface.

关键词： Rotor blade Large eddy simulation Film-cooling effectiveness Turbulence Rotation Subgrid-scale

Synthesis of TiO_2 nanoparticles in different thermal conditions and modeling its photocatalytic activity with artificial neural network

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Journal of Environmental Sciences 2012年第4期24卷 750-756页

作者： Fatemeh Ghanbary nasser Modirshahla Morteza Khosravi Mohammad Ali Behnajady Department of Applied Chemistry Faculty of ChemistryNorth Tehran BranchIslamic Azad UniversityTehran***Islamic Republic of Iran Research Laboratory Department of Applied ChemistryTabriz BranchIslamic Azad UniversityTabriz1655Islamic Republic of Iran

Titanium dioxide （TiO2） nanoparticles were prepared by sol gel route. The preparation parameters were optimized in the removal of 4-nitropbenol （4-NP）. All catalysts were analyzed by X-ray diffraction （XRD） and scanning electron microscopy （SEM）. An artificial neural network model （ANN） was developed to predict the photocatalytic removal of 4-NP in the presence of TiOz nanoparticles prepared under desired conditions. The comparison between the predicted results by designed ANN model and the experimental data proved that modeling of the removal process of 4-NP using artificial neural network was a precise method to predict the extent of 4-NP removal under different conditions.

关键词： nanoparticle TiO2 4-nitrophenol photocatalysis neural network modeling

ELASTIC MEMBRANE EQUATION WITH MEMORY TERM AND NONLINEAR BOUNDARY DAMPING:GLOBAL EXISTENCE,DECAY AND BLOWUP OF THE SOLUTION

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Acta Mathematica Scientia 2013年第1期33卷 84-106页

作者： Abderrahmane ZARA nasser-eddine TATAR Salem ABDELMALEK Depatment of Mathematics and Informatic Cheikh El Arbi Tébessi University12002 TébessaAlgeria Depatment of Mathematics and Statistics King Fahd University of Petroleum and MineralsDhahran 31261Saudi Arabia Depatment of Mathematics College of SciencesYanbuTaibah UniversitySaudi Arabia

In this paper we consider the Elastic membrane equation：with memory term and nonlinear boundary damping： Under some appropriate assumptions on the relaxation function h and with certain initial data, the global existence of solutions ：and a general decay for the energy are established using the multiplier technique. Also, ＇we show that a nonlinear source of polynomial type is able to force solutions to blow up in finite time even in presence of a nonlinear damping.

关键词： elastic membrane equation global existence boundary damping boundarysource general decay blowup

Developing a Super-lift Luo-converter with Integration of Buck Converters for Electric Vehicle Applications

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CSEE Journal of Power and Energy Systems 2021年第4期7卷 811-820页

作者： Behdad Faridpak Meisam Farrokhifar Mojtaba Nasiri Arman Alahyari nasser Sadoogi Faculty of Electrical and Computer Engineering University of TabrizTabriz ***Iran Center for Energy Science and Technology Skolkovo Institute of Science and TechnologyMoscow 121205Russia Solar Energy Applications Group School of EngineeringTrinity College DublinD02 PN40 DublinIreland Research and Development Department of Jam Hoor Tabriz Company Tabriz ***Iran

In this paper,a DC-DC multi-port converter is introduced by integrating a super-lift and a buck converter(SLBC).The proposed single-input dual-output(SIDO)converter has conventional positive output voltage super-lift advantages while simultaneously generating a step・up voltage by Luo・converter and a step-down voltage by the buck *** this structure,without utilizing electromagnetic components to generate a dual output,the ripple in output voltages is kept ***,the introduced SLBC has a simple structure and an appropriate control method providing a wide range of output ***,to illustrate the advantages of the proposed SIDO converter,a comparison with other similar configurations is carried ***,simulation and experiment results indicate a considerable reduction in conduction losses compared to other SIDO converters in the same *** operation accuracy of SLBC is validated by performing several simulations in PSCAD/EMTDC software and testing a 150W prototype in the laboratory.

关键词： DC-DC converter Luo-converter single-input dual-output(SIDO) super-lift(SL) high voltage gain

Optimization of Chiller Loading Problem Using Improved Golden Jackal Optimization Algorithm Leads to Reduction in Energy Consumption

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Energy Engineering 2023年第11期120卷 2565-2583页

作者： Na Dong Xiao Yang nasser Yousefi School of Mechanical Engineering Henan Institute of TechnologyXinxiang453000China School of Electrical Engineering and Automation Henan Institute of TechnologyXinxiang453000China Karaj Branch Islamic Azad UniversityKaraj***Iran College of Technical Engineering The Islamic UniversityNajaf54001Iraq

This paper proposes a modified golden jackal optimization(IGJO)algorithm to solve the OCL(which stands for optimal cooling load)problem to minimize energy *** this algorithm,many tools have been developed,such as numerical visualization,local field method,competitive selectionmethod,and iterative *** IGJO algorithm is used to improve the research capabilities of the algorithm in terms of global tuning and rotation *** order to fully utilize the effectiveness of the proposed algorithm,three famous examples of OCL problems in basic ventilation systems were studied and compared with some previously published *** results show that the IGJO algorithm can find solutions equal to or better than other *** these studies is the need to reduce energy consumption in air conditioning systems,which is a critical business and environmental *** Optimal Chiller Load(OCL)problem is well-known in the *** is the best method of operation for the refrigeration plant to satisfy the requirement of *** order to solve the OCL problem,an improved Golden Jackal optimization algorithm(IGJO)was *** IGJO algorithm consists of a number of parts to improve the global optimization and rotation *** studies are intended to address more effectively the issue of OCL,which results in energy savings in air-conditioning *** performance of the proposed IGJO algorithm is evaluated,and the results are compared with the results of three known OCL problems in the ventilation *** results indicate that the IGJO method has the same or better optimization ability as other methods and can improve the energy efficiency of the system’s cold air.

关键词： Optimal chiller loading improved version of golden jackal optimization energy consumption

Calculation of Hildebrand Solubility Parameters of Some Polymers Using QSPR Methods Based on LS-SVM Technique and Theoretical Molecular Descriptors

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Chinese Journal of Polymer Science 2014年第5期32卷 587-594页

作者： nasser Goudarzi M.Arab Chamjangali A.H.Amin Faculty of Chemistry Shahrood University of Technology

In this work, some chemometrics methods are applied for the modeling and prediction of the Hildebrand solubility parameter of some polymers. A genetic algorithm （GA） method is designed for the selection of variables to construct two models using the multiple linear regression （MLR） and least square-support vector machine （LS-SVM） methods in order to predict the Hildebrand solubility parameter. The MLR method is used to build a linear relationship between the molecular descriptors and the Hildebrand solubility parameter for these compounds. Then the LS-SVM method is utilized to construct the non-linear quantitative structure-activity relationship （QSAR） models. The results obtained using the LS-SVM method are then compared with those obtained for the MLR method; it was revealed that the LS-SVM model was much better than the MLR one. The root-mean-square errors of the training set and the test set for the LS-SVM model were 0.2912 and 0.2427, and the correlation coefficients were 0.9662 and 0.9518, respectively. This paper provides a new and effective method for predicting the Hildebrand solubility parameter for some polymers, and also reveals that the LS-SVM method can be used as a powerful chemometrics tool for the quantitative structure-property relationship （QSPR） studies.

关键词： Hildebrand solubility parameter Least square-support vector machine (LS-SVM) Quantitative structure- property relationship (QSPR) Multiple linear regression (MLR) Genetic algorithm (GA).

Holographic memory-based Bayesian optimization algorithm (HM-BOA) in dynamic environments

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Science China(Information Sciences) 2013年第9期56卷 110-126页

作者： KAEDI Marjan GHASEM-AGHAEE nasser AHN Chang Wook Department of Information technology Engineering University of Isfahan Department of Computer Engineering University of Isfahan Department of Computer Engineering Sungkyunkwan University

This paper presents a new evolutionary dynamic optimization algorithm, holographic memory-based Bayesian optimization algorithm (HM-BOA), whose objective is to address the weaknesses of sequential memory-based dynamic optimization approaches. To this end, holographic associative neural memory is applied to one of the recent successful memory-based evolutionary methods, DBN-MBOA (memory-based BOA with dynamic Bayesian networks). Holographic memory is appropriate for encoding environmental changes since its stimulus and response data are represented by a vector of complex numbers such that the phase and the magnitude denote the information and its confidence level, respectively. In the learning process in HM-BOA, holographic memory is trained by probabilistic models at every environmental change. Its weight matrix contains abstract information obtained from previous changes and is used for constructing a new probabilistic model when the environment changes. The unique features of HM-BOA are: 1) the stored information can be generalized, and 2) a small amount of memory is required for storing the probabilistic models. Experimental results adduce grounds for its effectiveness especially in random environments.

关键词： dynamic optimization Bayesian optimization algorithm holographic memory dynamic Bayesian networks.

Modelling and control of a grid-connected AC microgrid with the integration of an electric vehicle

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Clean Energy 2023年第4期7卷 707-720页

作者： Youssef Akarne Ahmed Essadki Tamou nasser Hammadi Laghridat Higher National School of Arts and Crafts(ENSAM) Mohammed V UniversityRabatMorocco National High School for Computer Science and Systems Analysis(ENSIAS) Mohammed V UniversityRabatMorocco

The purpose of this paper is to propose an efficient model and a robust control that ensures good power quality for the AC microgrid(MG)connected to the utility grid with the integration of an electric vehicle(EV).The MG consists of two renewable energy sources:a photovoltaic system(PVS)and a wind turbine system(WTS)based on a permanent magnet synchronous generator(PMSG),with the integration of an *** sources are used to supply active and reactive power to the AC bus and the utility *** power point tracking(MPPT)based on the perturb-and-observe(PO)method is used to increase the efficiency of the photovoltaic modules and improve overall *** MG system includes a 2-MW WTS,a 100-kW PVS and 12 kW provided by the *** validate the performance of the proposed system,a series of simulations were conducted using the MATLAB/Simulink?*** results demonstrate that the proposed system ensures high performance in terms of power quality,system stability,power tracking and safe integration of the EV.

关键词： microgrid wind turbine system photovoltaic system electric vehicle grid-to-vehicle vehicle-to-grid control systems

Effects of Rate and Source Organo-Mineral Material on Forage Yield and Nutritive Value of Barley-Pea Mixed under Arid Conditions

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Phyton-International Journal of Experimental Botany 2022年第7期91卷 1483-1493页

作者： Walid Soufan nasser A.Al-Suhaibani Plant Production Department College of Food and Agriculture SciencesKing Saud UniversityRiyadh11451Saudi Arabia

Cereal-legume intercropping plays a vital role in the subsistence food production system that prevails in the arid *** not only provides profitable crop productivity for agricultural communities but also plays an important role in improving soil ***,the present research was conducted to assess the effect of the organic and mineral fertilizers on the forage yield and nutritional value in barley-pea intercropping *** results revealed that the quality of forage grass is significantly influenced by both organic and inorganic ***,organic fertilizer application has significantly influenced the dry matter(DM),crude ash(CA),crude protein(CP),neutral detergent fiber(NDF),and acid detergent fiber(ADF).Among the treatments,organic fertilizer added at rate of 35 m^(−3) ha^(−1) produced the maximum fresh and dry matter in barley and *** addition,the same level of organic fertilizer also improved silage composition by significantly increasing the protein and fiber content and showed highest the *** on overall results,it is concluded that organic fertilizer treatment(35 m^(−3) ha^(−1))has the potential as an effective strategy to improve the productivity and nutritional quality of the barley-pea intercropping system in arid *** results revealed that organic fertilizer can be utilized in sustainable agricultural as a source of nutrients for numerous various crops under arid conditions.

关键词： Organic fertilizer barley pea yield quality hay silage