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Effect of splitter leading edge location on performance of an automotive turbocharger compressor
, Article Energy ; Volume 123 , 2017 , Pages 511-520 ; 03605442 (ISSN) ; Hajilouy Benisi, A ; Durali, M ; Sharif University of Technology
Elsevier Ltd
2017
Abstract
Design of centrifugal compressors can be accomplished using methods provided in text books and open literature. In this general approach, after determination of dimensions in meridional plane, blade profiles are designed using aerodynamic methods. Then, some blades are trimmed at the beginning to avoid inlet blockage. But there is no clear guidance on how this trimming must be performed. With this widely implemented method, splitter blades have the same profile as main ones. In this research, blade profiles and dimensions of the compressor impeller are not changed while the effect of changes in the position and angle of splitters leading edge are investigated. An optimization scheme is...
Multilevel optimization of the splitter blade profile in the impeller of a centrifugal compressor
, Article Scientia Iranica ; Volume 24, Issue 2 , 2017 , Pages 707-714 ; 10263098 (ISSN) ; Hajilouy Benisi, A ; Durali, M ; Sharif University of Technology
Sharif University of Technology
2017
Abstract
In this research, multi-level optimization of the profile of the splitter blades of a turbocharger compressor is performed using genetic algorithm in order to improve its performance. Successive corrections of the profile at hub, mid-span, and shroud of the splitter blades, with the objective of decreasing the incidence losses at the leading edge and adjustment of the blade loading at the shroud, result in an impeller having improved splitter blades. The impeller flow field analysis shows that the optimization has been successful in reducing the flow leakage at the shroud region as well as the losses in the leading edge region. Although numerical simulations predict a decrease by 0.5% in...
Learning improvement by using matlab simulator in advanced electrical machine laboratory
, Article RPC 2010 - 1st Russia and Pacific Conference on Computer Technology and Applications, 6 September 2010 through 9 September 2010 ; 2010 , Pages 107-116 ; Fazly, M ; Sharif University of Technology
2010
Abstract
This paper presents how can teach complicated problems in electrical engineering subjects (electrical machines) by using simulators such as MATLAB/SIMULINK. Simulation of direct vector control of induction machine (IM) drive on the rotor flux direction with composite model flux observer can improve electrical machine teaching-learning procedure for graduated and under graduated levels. In the indirect vector control of IM, current reference values are used for estimation angle of the rotor flux space vector (ARFSV), however using current reference values instead of current real values can decrease accuracy of ARFSV. In the direct vector control, current real values (current feedback)...
Degradation of humic acids through heterogeneous catalytic ozonation with bone charcoal
, Article Reaction Kinetics, Mechanisms and Catalysis ; Volume 100, Issue 2 , 2010 , Pages 471-485 ; 18785190 (ISSN) ; Asgari, Gh ; Hashemian, S. J ; Moussavi, G ; Sharif University of Technology
2010
Abstract
Catalytic ozonation has recently been used as a new means of contaminant removal from water and wastewater. In this study, bone charcoal (BC), a new catalyst prepared under laboratory conditions, was used to catalyze the ozonation of humic substances (HS) in aqueous solutions. The catalytic effect of bone charcoal and the relevant parameters of this ozonation process (solution pH, temperature, scavenger effect, humic acids concentration and BC dosage) were investigated. In the catalytic ozonation experiments, the degradation kinetics was investigated. The reaction rate and the rate constant were determined. The results showed that using a BC catalyst in the ozonation of HS produced a 1.43-...
Numerical optimization and manufacturing of the impeller of a centrifugal compressor by variation of splitter blades
, Article ASME Turbo Expo 2016, Turbomachinery Technical Conference and Exposition, 13 June 2016 through 17 June 2016 ; Volume 8 , 2016 ; 9780791849866 (ISBN) ; Hajilouy Benisi, A ; Durali, M ; International Gas Turbine Institute ; Sharif University of Technology
American Society of Mechanical Engineers (ASME)
2016
Abstract
Design and optimization of centrifugal compressors, based on main blades configuration of impeller have been vastly discussed in open literature, but less researches have addressed splitters. In this research, the impeller of a commercial turbocharger compressor is investigated. Here, profiles of main blades are not changed while the effect of changing the configuration of splitters is studied. An optimization study is performed to find the best configuration using genetic algorithm over a complete operating curve of the compressor. CFD codes with experimental support are used to predict the compressor performance. Quantumetric tests beside destructive analysis of two impellers are...
Experimental and numerical investigations of radial flow compressor component losses
, Article Journal of Mechanical Science and Technology ; Vol. 28, issue. 6 , 2014 , p. 2189-2196 ; Hajilouy-Benisi, A ; Abolfazl Moussavi-Torshizi, S ; Movahhedy, M.R ; Durali, M ; Sharif University of Technology
2014
Abstract
This research numerically and experimentally investigates a small turbocharger radial flow compressor with a vane-less diffuser and volute. The geometry of the compressor is obtained via component scanning, through which a 3D model is prepared. The flow inside this model is numerically analyzed by using a Navier-Stokes solver with a shear-stress transport turbulence model. The characteristic curves of the compressor and the contributions of its components to total pressure drop are acquired by measuring the static and total pressures at different cross sections of the compressor. Numerical results are verified with the experimental test results. The model results exhibit good agreement with...
Decolorization of reactive blue 19 dye from textile wastewater by the UV/H2O2 process
, Article Journal of Applied Sciences ; Volume 8, Issue 6 , 2008 , Pages 1108-1112 ; 18125654 (ISSN) ; Ghaneian, M. T ; Hashemian, S. J ; Moussavi, G ; Khavanin, A ; Ghanizadeh, G ; Sharif University of Technology
Asian Network for Scientific Information
2008
Abstract
Photo-oxidation of dyes is a new concern among researchers since it offers an attractive method for decoloration of dyes and breaks them into simple mineral forms. An advanced oxidation process, UV/H2O2, was investigated in a laboratory scale photoreactor for decolorization of the Reactive blue 19 (RB19 dye from synthetic textile wastewater. The effects of operating parameters such as hydrogen peroxide dosage, pH, initial dye concentration and UV dosage, on decolorization have been evaluated. The RB19 solution was completely decolorized under optimal hydrogen peroxide dosage of 2.5 mmol L-1 and low-pressure mercury UV-C lamps (55 w) in less than 30 min. The decolorization rate followed...
Design and Prototyping a High Speed 60 kW Spindle Incorporated Air Turbine
, M.Sc. Thesis Sharif University of Technology ; Durali, Mohammad (Supervisor)
Abstract
Regarding the price of industrial turbo machines, testing the rotating elements of them is always an important issue. One of the companies of the aviation industry decided to design and fabricate a spin tester device to check the quality of new rotating parts before installing them on gas turbines. A team has worked on this project for more than a one year. The present thesis is on designing the drive system of the spin tester. The drive system was chosen to be an air motor. This thesis concentrates on the design procedure of this air motor. The designed system is capable of providing enough power to accelerate the disks to the test speed in the appropriate time. The disk geometry, test...
Photochemical oxidation of Reactive blue 19 dye (RB19) in textile wastewater by UV/K2S2O8 process
, Article Iranian Journal of Environmental Health Science and Engineering ; Volume 5, Issue 2 , 2008 , Pages 95-100 ; 17351979 (ISSN) ; Ghaneian, M. T ; Khavanin, A ; Hashemian, S. J ; Moussavi, G. H ; Ghanizadeh, G. H ; Hajizadeh, E ; Sharif University of Technology
2008
Abstract
In textile industry, advanced oxidation processes are used for degrading and removing color from dye baths which allow wastewater reuse. In this study, photochemical oxidation processes (UV-A/K2S2O8, UV-C/ K2S2O8) and chemical oxidation process (dark/K2S2O8), were investigated in a laboratory scale photoreactor for decolorization of the Reactive blue 19 (RB19) dye from synthetic textile wastewater. The effects of operating parameters such as potassium persulphate dosage, pH, reaction time and UV source, on decolorization have been evaluated. The results of direct chemical oxidation showed that 50% of the dye was been removed using K2S2O8 in dark condition after 5h reaction time and...
An innovative, highly stable Ag/ZIF-67@GO nanocomposite with exceptional peroxymonosulfate (PMS) activation efficacy, for the destruction of chemical and microbiological contaminants under visible light
, Article Journal of Hazardous Materials ; Volume 413 , 2021 ; 03043894 (ISSN) ; Giannakis, S ; Moussavi, G ; Bensimon, M ; Gholami, M. R ; Pulgarin, C ; Sharif University of Technology
Elsevier B.V
2021
Abstract
In this work, Ag nanoparticles were loaded on ZIF-67 covered by graphene oxide (Ag/ZIF-67@GO), and its catalytic performance was studied for the heterogeneous activation of peroxymonosulfate (PMS) under visible-light. The catalyst surface morphology and structure were analyzed by FT-IR, XRD, XPS, DRS, FE-SEM, EDX, TEM, BET, ICP-AES and TGA analysis. The efficacy of PMS activation by the Ag/ZIF-67@GO under visible light was assessed by phenol degradation and E. coli inactivation. Phenol was completely degraded within 30 min by HO•, SO4•− and O2•− generated through the photocatalytic PMS activation. In addition, total E. coli inactivation was attained in 15 min that confirmed the highly...
Modifications in Commercial Diesel Engines to Perform Under Difficult Respiration Conditions
, M.Sc. Thesis Sharif University of Technology ; Durali, Mohammad (Supervisor)
Abstract
In this project we are about to adopt a method for implementing commercial diesel engines (truck and bus engines) in applications with difficult respiration condition like what happens in a submarine. To this end, working conditions of such engines are introduced and standard constraints are explained. Then the structure of already manufactured submarine engines is presented. At this point an engine from known manufacturers was selected for calculations to be performed on it. Since test and measurement equipments were not yet ready, simulation using computer software (GT-POWER v6.1) was selected as the solving method. First, the engine was modeled in its nominal working conditions. After...
Design, Optimization and Numerical and Experimental Investigation of the Impeller of a Centrifugal Compressor under Geometric Constraints
, Ph.D. Dissertation Sharif University of Technology ; Hajilouy Benisi, Ali (Supervisor) ; Durali, Mohammad (Supervisor)
Abstract
Centrifugal compressors are vastly implemented in the industry due to their higher pressure ratio per stage. So, researches are still going on to improve the performance of these devices. On this way, the current project is defined to perform geometrical optimization in the impeller of a centrifugal compressor using numerical and experimental methods. In this research, the design process of centrifugal compressors is first discussed according to methods and guidelines provided in several references. Then the compressor of the GT4082 turbocharger is redesigned using these theories. It is shown that overall available rules are enough to design an acceptable centrifugal compressor. Experimental...
Mathematical study of probe arrangement and nanoparticle injection effects on heat transfer during cryosurgery
, Article Computers in Biology and Medicine ; Volume 66 , Nov , 2015 , Pages 113-119 ; 00104825 (ISSN) ; Ramazani S. A. A ; Nazemidashtarjandi, S ; Sharif University of Technology
Elsevier Ltd
2015
Abstract
Blood vessels, especially large vessels have a greater thermal effect on freezing tissue during cryosurgery. Vascular networks act as heat sources in tissue, and cause failure in cryosurgery and reappearance of cancer. The aim of this study is to numerically simulate the effect of probe location and multiprobe on heat transfer distribution. Furthermore, the effect of nanoparticles injection is studied. It is shown that the small probes location near large blood vessels could help to reduce the necessary time for tissue freezing. Nanoparticles injection shows that the thermal effect of blood vessel in tissue is improved. Using Au, Ag and diamond nanoparticles have the most growth of ice ball...
Mechanical, rheological and oxygen barrier properties of ethylene vinyl acetate/diamond nanocomposites for packaging applications
, Article Diamond and Related Materials ; Volume 99 , 2019 ; 09259635 (ISSN) ; Ramazani S. A., A ; Haddadi, S. A ; Kheradmand, A ; Sharif University of Technology
Elsevier Ltd
2019
Abstract
In this work, the effects of the surface-modified nanodiamond particles (NDs) on the barrier, rheological, mechanical and thermal properties of ethylene vinyl acetate (EVA) composites for the packaging applications were investigated. Fourier transform infrared spectroscopy, as well as thermal gravimetric analysis were employed to study the grafting of vinyltriethoxy silane (VTS) on the surface of NDs. Afterwards, EVA samples containing 0, 0.1, 0.5, 1, 1.5 and 2 wt% of surface-modified NDs were prepared by a two-stage process including the solution and injection processes. In order to evaluate the physicochemical, rheological, mechanical and thermal properties of the EVA/NDs samples, field...
Effect of bonding parameters on microstructure development during TGTLP bonding of Al7075 alloy
, Article Philosophical Magazine ; Vol. 94, issue. 11 , Mar , 2014 , pp. 1166-1176 ; ISSN: 14786435 ; Ekrami, A ; Farahany, S ; Jahangiri, A ; Sharif University of Technology
2014
Abstract
The effect of temperature, pressure and bonding time on microstructure of temperature gradient transient liquid phase (TGTLP) diffusion bonded Al7075 alloy using liquid gallium interlayer was investigated. The selected bonding method relies on using the minimum amount of liquid gallium on faying surfaces, using a very fast heating rate to reach the joining temperature and imposing a temperature gradient across the bond region. The microstructure of the diffusion bonded joints was evaluated by light optical microscopy, scanning electron microscopy and energy dispersive spectroscopy (EDS). Results show that by increasing the temperature, pressure and time of joining, a more uniform...
Kalman filter based packet loss replacement in presence of additive noise
, Article 2012 25th IEEE Canadian Conference on Electrical and Computer Engineering: Vision for a Greener Future, CCECE 2012 ; 2012 ; 9781467314336 (ISBN) ; Ghorshi, S ; Tahaei, A
2012
Abstract
A major problem in real-time packet-based communication systems, is misrouted or delayed packets which results in degraded perceived voice quality. If packets are not available on time, the packets are considered as lost. The easiest solution in a network terminal receiver is to replace silence for the duration of lost speech segments. In a high quality communication system, to avoid degradation in speech quality due to packet loss, a suitable method or algorithm is needed to replace the missing segments of speech. In this paper, we introduce an adaptive filter for replacement of lost speech segment. In this method Kalman filter as a state-space based method will be used to predict the...
Thermal behavior of alkaline lead acetate, a study of thermogravimetry and differential scanning calorimetry
, Article Scientia Iranica ; Volume 15, Issue 4 , 2008 , Pages 435-439 ; 10263098 (ISSN) ; Alamolhoda, A. A ; Hashemian, S. J ; Sharif University of Technology
Sharif University of Technology
2008
Abstract
The compound, alkaline lead acetate, Pb(CH3COO)2·PbO·H2O (ALA), was purchased from the Fluka Company. The X-ray diffraction film and SEM electron microgaph of this compound were obtained and reported in this paper for the first time. The thermal behavior of alkaline lead acetate (ALA) was studied using thermogravimetery (TGA) and Differential Scanning Calorimetery (DSC) techniques under an O2 gas atmosphere from 25 to 600°C. Four distinct energy changes associated with weight changes were observed, all of them being exothermic in the DSC results. The amount of ΔH for each peak is reported. © Sharif University of Technology
Study of thermal behavior of α-PbO2, using TG and DSC
, Article Journal of Thermal Analysis and Calorimetry ; Volume 92, Issue 3 , 2008 , Pages 917-920 ; 13886150 (ISSN) ; Alamolhoda, A. A ; Hashemian, S. J ; Sharif University of Technology
2008
Abstract
Using two techniques of thermogravimetry and differential scanning calorimetry under O2 gas atmosphere from 25 to 600°C, the thermal behavior of laboratory-produced compound lead(IV) oxide α-PbO2 was investigated. The identity of products at different stages were confirmed by XRD technique. Both techniques produced similar results supporting the same decomposition stages for the compound. Three distinct energy changes were observed, namely, two endothermic and one exothermic in DSC. The amount of ΔH for each peak is also reported. © 2008 Springer Science+Business Media, LLC
Effect of reactive diluent on gas separation behavior of photocurable acrylated polyurethane composite membranes
, Article Journal of Applied Polymer Science ; Volume 137, Issue 3 , 15 January , 2020 ; Shojaei, A ; Mousavi, S. A ; Ahmadi, S. A ; Sharif University of Technology
John Wiley and Sons Inc
2020
Abstract
In this study, the effects of the type and content of reactive diluents on the permeation/separation of carbon dioxide/nitrogen (CO2/N2) through acrylate-terminated polyurethane (APU)-acrylate/acrylic diluent (APUA) composite membranes was investigated. A series of APUs based on poly(ethylene glycol) (PEG)-1000 g mol−1, toluene diisocyanate, and 2-hydroxyethyl methacrylate was synthesized and then diluted with several reactive diluents. The results obtained from differential scanning calorimetry (DSC) and Fourier transform infrared analyses showed that the microphase interference of hard and soft segments increased with increasing reactive diluent content. Furthermore, with increasing alkene...
An investigation into the structure and thermal properties of lead hydroxide
, Article Scientia Iranica ; Volume 14, Issue 2 , 2007 , Pages 169-173 ; 10263098 (ISSN) ; Alamolhoda, A. A ; Hashemian, S. J ; Sharif University of Technology
Sharif University of Technology
2007
Abstract
The compound, lead hydroxide Pb6O4(OH)4, was prepared by a method used for the first time in the authors laboratory. The compound was identified by XRD and it's purity was determined by analytical methods (100%). The thermal characteristics of this compound were investigated by using a thermogravimetry (TGA). This compound was found to be stable at room temperature and at 160°C will decompose completely to produce lead (II) oxide. © Sharif University of Technology, April 2007