Loading...
Search for: ghorbanian--k
0.01 seconds

    Design and optimization of a cascade thermoacoustic Stirling engine

    , Article Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy ; Volume 227, Issue 7 , September , 2013 , Pages 814-824 ; 09576509 (ISSN) Karimi, M ; Ghorbanian, K ; Sharif University of Technology
    Professional Engineering Publishing  2013
    Abstract
    This article deals with the design and optimization of a cascade thermoacoustic Stirling engine. Different configurations for cascade thermoacoustic Stirling heat engine are investigated. A simplified model is proposed to enable initial design guidelines. The most important characteristics of the cascade system are examined. The results indicate that the thermoacoustic engines in cascade configuration may achieve very low onset temperatures. A suitable configuration is selected and the locations and dimensions of different thermoacoustic units are optimized to achieve low onset temperatures as well as high values for the acoustic power output and efficiency. The results support the... 

    Thermoeconomic approach for optimal design of gas turbine heat recovery steam generator

    , Article Proceedings of the 26th International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems, ECOS 2013 ; July , 2013 Hanafizadeh, P ; Parhizgar, T ; Ghorbanian, K ; Sharif University of Technology
    China International Conference Center for Science and Technology  2013
    Abstract
    In the present study a comprehensive thermoeconomic modelling of a heat recovery steam generator (HRSG) for a typical 4MW class gas turbine is performed. Usually, the thermoeconomic analyses involve a thermodynamic model of the HRSG and an economic model dedicated to assess the cost. In this study, different configurations of single and dual pressure level HRSGs are optimized and afterward compared to find the economical design. For these configurations thermodynamic model calculates the performance and the energy balance of systems at the optimal operating conditions which are derived from optimization model, and economic model estimates total cost per unit of produced energy. Finally,... 

    Investigation of the pressure distribution and transition point over a swept wing

    , Article Scientia Iranica ; Volume 18, Issue 6 , December , 2011 , Pages 1277-1286 ; 10263098 (ISSN) Soltani, M. R ; Ghorbanian, K ; Masdari, M ; Sharif University of Technology
    2011
    Abstract
    A series of wind tunnel tests are performed to examine the flow field over a swept wing under various conditions. The wing has a laminar flow airfoil section, similar to those of the NACA 6-series. Static pressure distributions over the upper surface of the wing, in both chordwise and spanwise directions, are measured at different angles of attack. The data is employed to predict the transition point at each chordwise section. The skewness parameter of the pressure data shows that this factor drops to zero in the transition region. A comparison of the calculated transition point on the wing surface with that obtained from the 2D computational method shows reasonable agreement over a portion... 

    Energy and exergy analyses of an integrated gas turbine thermoacoustic engine

    , Article Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy ; Volume 225, Issue 4 , June , 2011 , Pages 389-402 ; 09576509 (ISSN) Karimi, M ; Ghorbanian, K ; Gholamrezaei, M ; Sharif University of Technology
    2011
    Abstract
    In this article, an attempt is made to utilize the exhaust gases of a small gas turbine to augment power output through the employment of a thermoacoustic system. A simple gas turbine cycle is selected as the base cycle and it is assumed that the thermoacoustic system is powered only by the waste heat of the base gas turbine. A comprehensive cycle analysis of the integrated gas turbine thermoacoustic engine (IGTTE) is carried out from an energy and exergy point of view. Exergy efficiency and internal exergy efficiency are calculated for the different components of the base gas turbine engine as well as the IGTTE. Value and exergy flow diagrams are used to investigate the possible... 

    Application of integrated fuzzy logic and neural networks to the performance prediction of axial compressors

    , Article Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy ; Volume 229, Issue 8 , 2015 , Pages 928-947 ; 09576509 (ISSN) Gholamrezaei, M ; Ghorbanian, K ; Sharif University of Technology
    SAGE Publications Ltd  2015
    Abstract
    An integrated fuzzy logic-neural network methodology is presented as a mean to improve the reconstruction of the performance map of axial compressors and fans. The learning capability of artificial neural network technique is integrated to the knowledge aspect of fuzzy inference system to offer enhanced prediction capabilities compared to using a single methodology independently. The proposed technique incorporates information of experimental data on surge, operating, and choke lines at any arbitrary but fixed rotational speed. A comparison of the predicted results with experimental data reveals a very good agreement. The proposed technique has the capability to model the nonlinear surge... 

    Compressor map generation using a feed-forward neural network and rig data

    , Article Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy ; Volume 224, Issue 1 , 2010 , Pages 97-108 ; 09576509 (ISSN) Gholamrezaei, M ; Ghorbanian, K ; Sharif University of Technology
    Abstract
    In this article, a feed-forward neural network is explored to reconstruct the performance map of an axial compressor through the utilization of a limited number of experimental data. The Levenberg-Marquardt algorithm with Bayesian regularization method is used to adjust the weights and biases of the network. The proposed technique is utilized to estimate the mass flowrate, the pressure ratio, the shaft speed, and the efficiency in regions where no experimental data are available. The surge line is predicted and the line of maximum efficiencies is determined. The results are compared with experimental data  

    Reflected shock tube experiments on aeroacoustic signature of hot jets

    , Article Journal of Mechanical Science and Technology ; Volume 31, Issue 8 , 2017 , Pages 3811-3820 ; 1738494X (ISSN) Jahromi, I. B ; Ebrahimi, M ; Ghorbanian, K ; Sharif University of Technology
    Abstract
    We used a reflected shock tube to investigate the acoustic signature of a hot jet at the far-field. Experiments were performed at Mach = 1.4 and a total temperature of Tt = 950 Kelvin. Far-field acoustic signatures of the hot jet at six polar angles θ = 15˚ to θ = 90˚ from the jet axis) were measured and imaged by the means of continuous wavelet transform in scalograms. The results were compared with experiments from a steady test facility at similar test conditions. Further, the primary characteristics of noise events in jet far-field were compared with analytical models considering wavepacket as the main source of jet noise. The results indicate that higher frequency events at θ = 90˚... 

    Control of pressure gradient in the contraction of a wind tunnel

    , Article World Academy of Science, Engineering and Technology ; Volume 40 , 2009 , Pages 261-266 ; 2010376X (ISSN) Dehghan Manshadi, M ; Mirzaei, M ; Ghorbanian, K ; Sharif University of Technology
    2009
    Abstract
    Subsonic wind tunnel experiments were conducted to study the effect of tripped boundary layer on the pressure distribution in the contraction region of the tunnel. Measurements were performed by installing trip strip at two different positions in the concave portion of the contraction. The results show that installation of the trip strips, have significant effects on both turbulence and pressure distribution. The reduction in the free stream turbulence and reduction of the wall static pressure distribution deferred signified with the location of the trip strip  

    Rotated general regression neural network

    , Article 2007 International Joint Conference on Neural Networks, IJCNN 2007, Orlando, FL, 12 August 2007 through 17 August 2007 ; 2007 , Pages 1959-1964 ; 10987576 (ISSN) ; 142441380X (ISBN); 9781424413805 (ISBN) Gholamrezaei, M ; Ghorbanian, K ; Sharif University of Technology
    2007
    Abstract
    A rotated general regression neural network is presented as an enhancement to the general regression neural network. A variable kernel estimate for multivariate densities is considered. A coordinate transformation is adopted which circumvent the difficulty of predicting multimodal distribution with large variance differences between modes which is associated with the general regression neural network. The proposed technique trains the network in a way that the variance differences between modes is kept small and in the same order. Further, the technique reduces the number of indispensable training parameters to two parameters and lowers the load of the computation as well as the time for... 

    Numerical investigation of transient thermo-fluid processes in a Ranque-Hilsch vortex tube

    , Article International Journal of Refrigeration ; Volume 131 , 2021 , Pages 746-755 ; 01407007 (ISSN) Mirjalili, M ; Ghorbanian, K ; Sharif University of Technology
    Elsevier Ltd  2021
    Abstract
    A 2D numerical investigation is performed to better understand the transient thermo-fluid processes in a vortex tube for a cold mass fraction equal to0.44. The results along the Ranque-Hilsch vortex tube reveal a close agreement with past numerical and experimental data. The distribution of axial, radial, and tangential velocities as well as the stagnation pressure and temperature are examined at different positions for different time steps. The results indicate that the tangential velocity is the most significant velocity component and dominates the heat transfer and energy conversion processes. In addition, it is evident that the core of the cold end experiences the highest pressure... 

    Experimental study on correlation between turbulence and sound in a subsonic wind tunnel

    , Article Acta Mechanica Sinica/Lixue Xuebao ; Volume 26, Issue 4 , 2010 , Pages 531-539 ; 05677718 (ISSN) Dehghan Manshadi, M ; Ghorbanian, K ; Soltani, M. R ; Sharif University of Technology
    Abstract
    In this paper, the effects of turbulence on sound generation and velocity fluctuations due to pressure waves in a large subsonic wind tunnel are studied. A trip strip located at different positions in the contraction part or at one position in the diffuser of a large wind tunnel is used to investigate the aforementioned phenomenon, and the results indicate that the trip strip has significant effects on sound reduction. The lowest turbulence intensity and sound are obtained from a trip strip with a diameter of 0.91mm located either at X/L = 0.79 or at X/L = 0.115 in the wide portion of the contraction. Furthermore, the effect of monopole, dipole and quad- rupole sources of aerodynamic noise... 

    Application of screens and trips in enhancement of flow characteristics in subsonic wind tunnels

    , Article Scientia Iranica ; Volume 17, Issue 1 B , 2010 , Pages 1-12 ; 10263098 (ISSN) Soltani, M. R ; Ghorbanian, K ; Manshadi, M. D ; Sharif University of Technology
    2010
    Abstract
    Subsonic wind tunnel experiments were conducted to study the turbulence level in the test section. Measurements were performed by introducing trip strip and/or damping screens on the flow field. The results indicated that the introduction of trip strips not only reduced the turbulence intensity compared to cases without it, but also flattened the variations. Further, the experiments which investigated the impact of the damping screens indicated a similar reduction in turbulence intensity; the pattern, however, remained the same. Furthermore, the results for cases wherein both trip strips as well as damping screens were placed on the contraction and in the settling chamber, respectively,... 

    An innovative genetic algorithm approach for direct calibration of X-probe hot wires

    , Article Experimental Techniques ; Volume 36, Issue 1 , MAR , 2012 , Pages 50-60 ; 07328818 (ISSN) Manshadi, M. D ; Keshavarz, B ; Soltani, M. R ; Ghorbanian, K ; Sharif University of Technology
    2012
    Abstract
    A new genetic algorithm (GA) based method for direct calibration of 2-D hot-wire probe and other instruments that can measure 2-D flow properties is introduced. This new method is an alternative for the previous QR method that is commonly used for calibration of the X-probe hot wires. The proposed GA method resulted in a much smaller error in the velocity estimation while preserving the number of sentences in its calibration equation format. In addition, it preserves the magnitude of its error even when the number of sentences in the calibration equation is decreased while the error in the QR method increases substantially for the same situation. Furthermore, the results were much closer to... 

    Power spectrum and FFT-based signal analysis in turbulence measurements

    , Article World Academy of Science, Engineering and Technology ; Volume 40 , 2009 , Pages 275-278 ; 2010376X (ISSN) Dehghan Manshadi, M ; Tamadonfar, P ; Soltani, M. R ; Ghorbanian, K ; Masdari, M ; Sharif University of Technology
    2009
    Abstract
    In this research, the employment of an innovative but simple and cost effective method for turbulent reduction in a low speed wind tunnel is investigated and the effect of this turbulence reduction on the Power Spectrum and FFT-Based signals that obtained from Hot-wire Anemometry is studied. These terms represents the amount of power contained in the signals. Several situations are studied in this paper. One of these situations is when there are four screens in the settling chamber of the wind tunnel and after that by adding the trip strip in the contraction region of the wind tunnel the tests were repeated. In the next stage, three screens were removed from the settling chamber of the wind... 

    Unsteady three dimensional aerodynamic load prediction using neural networks

    , Article 2007 International Joint Conference on Neural Networks, IJCNN 2007, Orlando, FL, 12 August 2007 through 17 August 2007 ; 2007 , Pages 1995-1999 ; 10987576 (ISSN) ; 142441380X (ISBN); 9781424413805 (ISBN) Soltani, M. R ; Ghorbanian, K ; Gholamrezaei, M ; Amiralaei, M. R ; Sharif University of Technology
    2007
    Abstract
    The focus of the current research is to develop an intelligent design process that uses existing data as a tool for the designers, one that fully utilizes the ability of the computer to interpolate and extrapolate the scattered data. Surface pressure measurements were conducted for a pitch oscillation wing in a subsonic closed circuit wind tunnel. Experimental results have been used to train a multilayer perceptron network. This work indicates that neural networks can reliably predict aerodynamic coefficients and forecast the effects of reduced frequencies on the wind turbine blade performance. ©2007 IEEE  

    Application of multilayer perceptron network for unsteady three dimensional aerodynamic load prediction

    , Article 25th AIAA Applied Aerodynamics Conference, 2007, Miami, FL, 25 June 2007 through 28 June 2007 ; Volume 2 , 2007 , Pages 1197-1202 ; 10485953 (ISSN) ; 1563478986 (ISBN); 9781563478987 (ISBN) Gholamrezaei, M ; Soltani, M. R ; Ghorbanian, K ; Amiralaei, M. R ; Sharif University of Technology
    2007
    Abstract
    Surface pressure measurements were conducted for a pitch oscillation wing in a subsonic closed circuit wind tunnel. Experimental results have been used to train a multilayer perceptron network to foresee the effect of modification of oscillation amplitude and reduced frequency. Consistent results are obtained both for the training data as well as generalization to other amplitudes and reduced frequencies. This work indicates that artificial neural networks can reliably predict aerodynamic coefficients and forecast the effects of oscillation amplitude as well as reduced frequency on the wind turbine blade performance. Moreover, this study introduces a new tool for the designers to have enough... 

    A new design for tip injection in transonic axial compressors

    , Article 2006 ASME 51st Turbo Expo, Barcelona, 6 May 2006 through 11 May 2006 ; Volume 6 PART A , 2006 , Pages 39-47 ; 079184241X (ISBN); 9780791842416 (ISBN) Beheshti, B. H ; Ghorbanian, K ; Farhanieh, B ; Teixeira, J. A ; Ivey, P. C ; Sharif University of Technology
    2006
    Abstract
    This paper presents a state of the art design for the blade tip injection. The design includes the means, to inject high-pressure gas jet directly into a circumferential casing groove formed in the shroud adjacent to the blade tip. The casing groove is positioned over the blade tip and exceeds 30% of the blade axial chord beyond the impeller to both upstream and downstream directions. In order to validate the multi block model used in the tip gap region, main flow characteristics are verified with the experimental data for smooth casing with a design clearance of 0.5% span. Three arbitrary mass flow rates (1.75%, 2.45%, and 4.35% of choked mass flow) have been studied. The results indicate...