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sabzehparvar--milad
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Analysis of Blades Surface Effect on Wind Turbine Performance
, M.Sc. Thesis Sharif University of Technology ; Sadr Hosseini, Hani (Supervisor) ; Sabzehparvar, Mahdi (Supervisor)
Abstract
The development of wind turbine blades model that accurately predict wind turbine thrust in a full range of applicable wind speed has provided a powerful and reliable source for simulation of horizontal axis wind turbine power and thrust force that serves as a valuable tool for wind turbine design and performance analysis. A single-element blade model that reduces the rotor blade characteristics to a lift and drag coefficient vs. angle-of-attack formulation was found to describe accurately the rotor characteristics over a wide operating range. Measurements of wind speed and altitude of wind turbine installation location, rotor speed, and provided thrust is within less than 2% over a wide...
Synthesis of NiTi Nanoparticles by Electrical Discharge Method
, M.Sc. Thesis Sharif University of Technology ; Sadrnezhad, Khatiboleslam (Supervisor)
Abstract
Nickel-titanium nanoparticles showing shape memory properties at nanoscale, have recently attracted much attention as nanoactuators in the field of nano-electro-mechanical systems. So, spark discharge method was utilized in this study for synthesis of NiTi nanoparticles. First step was to design and build a suitable set-up for synthesis of nanoparticles with high qualities at a high production rate. Nextly, NiTi nanoparticles were synthesized from prealloyed electrodes at a positive pressure and were characterized by the EDS, XRD, SEM and DSC methods. The obtained product was as agglomerated nanoparticles having sizes of around 40nm with primary particle size of <10nm. Chemical composition...
Does the short-term boost of renewable energies guarantee their stable long-term growth? Assessment of the dynamics of feed-in tariff policy
, Article Renewable Energy ; Volume 159 , October , 2020 , Pages 1252-1268 ; Hamed Shakouri, G ; Mashayekhi, A. N ; Kazemi, A ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
Feed-in tariff (FiT) is one of the most efficient ways that many governments throughout the world use to stimulate investment in renewable energies (REs) technology. For governments, financial management of the policy could be challenging as it needs a considerable amount of budget to support RE producers during the long remuneration period. In this paper, it has been illuminated that the early growth of REs capacity could be a temporary boost. And the socio-economic structure of the system will backlash the policy if some social mechanisms are not considered. Social tolerance for paying REs tax and potential investors’ trust emanated from budget-related mechanisms -which have rarely been...
Aeroelastic stability consideration of supersonic flight vehicle using nonlinear aerodynamic response surfaces
, Article Journal of Fluids and Structures ; Volume 25, Issue 6 , 2009 , Pages 1079-1101 ; 08899746 (ISSN) ; Nobari, A. S ; Sabzehparvar, M ; Haddadpour, H ; Sharif University of Technology
2009
Abstract
Aeroelastic stability of a flexible supersonic flight vehicle is considered using nonlinear dynamics, nonlinear aerodynamics, and a linear structural model. Response surfaces including global multivariate orthogonal modeling functions are invoked to derive applied nonlinear aerodynamic coefficients. A modified Gram-Schmidt method is utilized to orthogonalize the produced polynomial multivariate functions, selected and ranked by predicted squared error metric. Local variation of angle-of-attack and side-slip angle is applied to the analytical model. Identification of nonlinear aerodynamic coefficients of the flight vehicle is conducted employing a CFD code and the required analytical model...
Aeroservoelastic behavior of supersonic guided flight vehicles
, Article Iranian Journal of Science and Technology, Transaction B: Engineering ; Volume 33, Issue 5 , 2009 , Pages 425-439 ; 10286284 (ISSN) ; Nobari, A ; Sabzehparvar, M ; Moghaddam, M. M ; Haddadpour, H ; Sharif University of Technology
2009
Abstract
Flight dynamics of the guided vehicle is modelled by the aid of linear and angular equations of motions using Lagrange's approach in this paper. Governing equations of the control system and the elastic behavior of the vehicle are added to the equations of dynamic states. Flexibility effect is modelled using the normal modes, generalized coordinates and forces. For validation of modified FORTRAN simulation code, the stability of specific vehicles is determined and compared with the same results in the literature. Using this code and by solving the governing equations for the desired flight vehicle, the aeroservoelasticity is analyzed and then the results are compared with the rigid cases and...