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    Defining a Resiliency Index for Urban Roadway Networks

    , M.Sc. Thesis Sharif University of Technology Soltani Nejad, Fatemeh (Author) ; Nassiri, Habibollah (Supervisor)
    Abstract
    Urban transportation infrastructure due to the emergency forces' access during and after the earthquake is one of the most important arteries in the face of crisis. The resilience of this infrastructure is a crucial factor that should control before an event, such as an earthquake, to prioritize segments for improving their conditions and prevent system disruption. In this research, a model presents for evaluating urban roads' resilience based on four characteristics of robustness, redundancy, resourcefulness, and rapidity. The fuzzy inference is employed to construct the model. Due to the expert opinion dependence of these models, the AHP questionnaire is used to train the model. In this... 

    Unsteady supersonic aerodynamics based on BEM, including thickness effects in aeroelastic analysis

    , Article Journal of Fluids and Structures ; Volume 19, Issue 6 , 2004 , Pages 801-813 ; 08899746 (ISSN) Soltani, N ; Esfahanian, V ; Haddadpour, H ; Behbahani Nejad, M ; Sharif University of Technology
    2004
    Abstract
    A general three-dimensional aeroelastic solver is developed based on coupled finite element and boundary element methods and applied to investigate the flutter boundaries in supersonic flows. The boundary element method is applied to three-dimensional unsteady supersonic potential flow as the aerodynamic model and coupled with the finite element method for structural modelling, in order to construct the system of aeroelastic equations. The aeroelastic equations are solved for the flutter prediction using the frequency domain approach. Flutter boundaries for two types of wing planforms at supersonic speeds are determined and compared with the existing experimental results and previous... 

    Characterization of V2O5 Spent Catalyst & Feasibility Study of its Regeneration

    , M.Sc. Thesis Sharif University of Technology Soltani Nejad, Mohammad (Author) ; Sadrnezhaad, Khatiboleslam (Supervisor) ; Farzami, Faezeh ($item.subfieldsMap.e)
    Abstract
    In this study, at first the V2O5 spent catalysts were characterized. The aim was to identifying whether these catalyst may be regenerated. Then, for feasibility study of them, three methods were applied: washing, diffusion and milling the spent catalysts for their subsequent reproduction. A variety of techniques such as XRD, XRF, AAS, TPR and TPO were applied in order to identify factors contributing in vanadium pentoxide catalysts deactivation. The results showed that approximately all of pollutants caused their performance deterioration, while they still have some active phases. Then, the polluted catalysts were washed (their yield increased from 43% to 72.2%). In the underside of the... 

    Experimental Study of the Pressure Distribution on the Surface of an Infinite Wing Influenced by Different Sweep Angles

    , M.Sc. Thesis Sharif University of Technology Tirandaz, Mohammad Rasoul (Author) ; Soltani, Mohammad Reza (Supervisor)
    Abstract
    A series of wind tunnel tests were performed to examine the effects of wing sweep and wing tip vortices on the pressure distribution of the upper surface of three wings with sweep angles of 23,33 and 40 degrees. The wing section had a laminar flow airfoil similar to that of NACA 6-series airfoils. All tests, were conducted at a chord Reynolds number of 8×〖10〗^5, and for a range of angle of attack -2 to14 degree. Generation of Wing tip vortices are eliminated by placing an End-plate on the wing tip. Static pressure distributions over the upper surface of the wing at three chordwise direction and at one spanwise direction along the quarter chord line are obtained. The results show that the... 

    Experimental Investigation of wake flow of a Supercritical Airfoil in Transonic Regime

    , M.Sc. Thesis Sharif University of Technology Abdi, Mohammad Ali (Author) ; Soltani, Mohammad Reza (Supervisor)
    Abstract
    Transonic flow study is important due to its vast applications. Supercritical airfoils are designed for transonic flow to postpone drag divergence and reduce the strength of shock. This type of airfoils are chiefly used in modern commercial airplanes because of their low drag in transonic regime and, as a result, reduction in their fuel consumption. Using supercritical airfoils needs accurate investigation of flow field due to several influential factors such as specific geometry, nonlinear nature of flow phenomena, and compressibility effects. However, the availability of experimental and numerical data for supercritical airfoils is less than that of the conventional ones. Thus,... 

    Non-Linear One-dimensional Dynamic Gas Turbine Simulation

    , M.Sc. Thesis Sharif University of Technology Jahanmardi, Fariba (Author) ; Soltani, Mohammad Reza (Supervisor)
    Abstract
    A new one-dimensional, time dependent aerothermodynamic mathematical model and computer simulation of the gas turbine engine has been developed and is introduced herein. This code simulates the transient and dynamic operation of the gas turbine engine bye solving conservation equations, expressed as one dimensional, time dependent Euler equations, with turbomachinery source terms. The various component models, which provide the turbomachinery source terms to Euler equations, are described. Bye incorporating both explicit and implicit equation solvers, transient simulation of the gas turbine engine can be conducted efficiently while maintaining the capability of simulating dynamic events.... 

    Investigation on Novel Methods of Precious Metals Recovery from Spent Catalysts

    , M.Sc. Thesis Sharif University of Technology Hassan Nejad, Hesam (Author) ; Kazemeini, Mohammad (Supervisor)
    Abstract
    High demand and price and restricted availability of Platinum Group Metals (PGMs) have made platinum recovery a major field of study for researchers and industries. Various methods have been introduced for this purpose. Ion exchange, leaching and liquid-liquid extraction (LLE) are just a few examples. Nowadays Solvent Extraction (SX) is one of the most challenging areas of study for platinum recovery from spent catalysts due to its simplicity and optimum cost. In this study, the commercial spent catalyst’s platinum was dissolved in aqua-regia after XRF analysis. Then it was extracted by the organic material Trioctylphosphineoxide diluted in toluene in the presence of Alkaline metal salts.... 

    Experimental Investigation of Buzz Frequency on an Axisymmetric Supersonic Air Intake Using Pressure Distribution on the Wind Tunnel Wall

    , M.Sc. Thesis Sharif University of Technology Bagheri, Maryam (Author) ; Soltani, Mohammad Reza (Supervisor) ; Farahani, Mohammad (Co-Advisor)
    Abstract
    Supersonic intakes with mixed compression has an appropriate performance in the critical point, but in the subcritical performance, when inlet mass flow rate is reduced to a certain amount, a self-sustained instability occurs in the flow. In this case, instability appears in the form of shock waves system oscillation which is called Buzz phenomenon. An axisymmetric supersonic air intake with mixed compression which is designed for a Mach number of 2 has been investigated experimentally in order to study buzz frequency. The intake has been experimented in different Mach numbers, angles of attack and mass flow rates. Besides, the intake with wind tunnel wall has been modeled and analyzed in... 

    Experimental Investigation of the Effects of Canard Position on the Flowfield Over the Wing of a Model

    , M.Sc. Thesis Sharif University of Technology Izadkhah, Mohammad (Author) ; Soltani, Mohammad Reza (Supervisor)
    Abstract
    The analysis results of air combat simulations explain fighters succeed at close air combat that are super maneuverable and at high angle of attack controllable. Closed-coupled delta wing/canard configurations play an important role in modern aircraft design. These configurations offer high trimmed lift, improved agility and maneuverability as well, as a potential for increased lift-to drag ratio, all of which make them attractive to study. Experiments were carried out in a subsonic closed circuit wind tunnel over a delta wing model under the influence of canard. Canard was set in two different vertical positions, high and mid, with respect to the wing location. Flowfield measurements were... 

    Investigation of the Effects of Reduced Frequency on the Surface Pressure of a Supercritical Airfoil in Transonic Regime

    , M.Sc. Thesis Sharif University of Technology Vaziri, Ehsan (Author) ; Soltani, Mohammad Reza (Supervisor)
    Abstract
    Supercritical airfoils are designed for transonic flow to reduce the strength of shock and its drag. These type of airfoils are used in design and construction of commercial airplanes because of their low drag in transonic regime and, as a result, a reduction in fuel consumption. Using supercritical airfoils needs accurate investigation of flow field due to several influential factors such as their specific geometry, nonlinear nature of flow phenomena, and compressibility effects. However, the availability of experimental and numerical data for supercritical airfoils is less than that for conventional airfoils. Thus, conducting experimental tests is essential for understanding of flow field... 

    Experimental Investigation of the Roughness Effects on the Pressure Distribution and Stationary Crossflow Instability over a Swept wing

    , M.Sc. Thesis Sharif University of Technology Damghani, Hamid (Author) ; Soltani, Mohammad Reza (Supervisor)
    Abstract

    Wind tunnel experiments are conducted to evaluate surface pressure distribution over a semi span swept wing with sweep angle of 33 degrees. The wing section has a laminar flow airfoil similar to that of NACA 6-series airfoils. The tests were conducted at speeds ranging from 50 to 70m/s with and without surface roughness. Surface static pressure was measured on the wing upper surface at three different chordwise rows located at the inboard station, (section 1, 2y/b=0.2), middle station, (section 2, 2y/b=0.43), and outboard station, (section 3, 2y/b=0.78). The differences between pressure distributions on the three sections of the wing were studied and the experimental results showed that... 

    Experimental Investigation of Reduced Frequency Effects on the Wake of an Airfoil in Plunging Motion

    , M.Sc. Thesis Sharif University of Technology Dallali, Maryam (Author) ; Soltani, Mohammad Reza (Supervisor)
    Abstract
    Wake aerodynamic of plunging airfoils have received less attention than the other unsteady phenomena. An experimental investigation was carried out to study the unsteady characteristics of flow field behind a model of a plunging airfoil in various conditions. The model has 0.25cm chord and is the 16m section of a 660kW wind turbine blade. All tests were conducted in the subsonic closed circuit wind tunnel in Iran. Invariable parameters were plunging amplitude, mean angle of attack and plunging frequency. The Wakes of plunging airfoil can be characterized as drag-producing, neutral, or thrust-producing .Our preliminary results show that the structure of vortex in the wake for the plunging... 

    Unstaedy Boundary Layer Measurement over an Airfoil in Plunging Motion

    , M.Sc. Thesis Sharif University of Technology Abdollahi, Rezvan (Author) ; Soltani, Mohammad Reza (Supervisor)
    Abstract
    An experimental investigation of unsteady boundary layer over a wind turbine blade conducted in a subsonic wind tunnel. The experiment performed at different positions along the airfoil chord. Model was oscillated with amplitude of ±5 cm. Reynolds number, based on airfoil chord, ranged 3˟105 upto 6.5˟105 and the reduced frequency ranged from 0.0055 to 0.0981. Velocity profile measured with a total pressure rake. The data were reduced via a low-pass filter. Increasing the reduced frequency, the velocity profile increases the level on turbulence fluctuation and becomes more attached to the surface.

     

    Investigation of the Effects of Reduced Frequency and Mean Angle of Attack on the Surface Pressure of a Supercritical Airfoil in Pitching Oscillation

    , M.Sc. Thesis Sharif University of Technology Shokri, Hossein (Author) ; Soltani, Mohammad Reza (Supervisor)
    Abstract
    Supercritical airfoils have been designed for transonic flow, however due to different flight conditions, the airfoil behavior during take-off and landing of the aircraft in subsonic flow regime must be known. Experimental and numerical information derived from supercritical airfoils are less than those of conventional airfoils. Because of the special geometry of supercritical airfoils and different phenomena that occurs through flow, using such airfoils even in steady states requires precise study/analysis of the flow. Therefore, one could benefit from experimental tests to better understand flow phenomena. The objective of the present research is the study effect of mean angle of attack... 

    An Experimental Investigation of Unsteady Flow Over a Delta Wing in Supersonic Regime

    , M.Sc. Thesis Sharif University of Technology Nazifi, Mohammad (Author) ; Soltani, Mohammad Reza (Supervisor)
    Abstract
    Focusing on unsteady flow field over delta wings due to vacuity of researches in this branch on one hand and requiring of modern aircrafts designers to this science on the other hand, expresses necessity of accomplishing present investigation. Scrutiny of pressure distribution of low aspect ratio wings in unsteady state and determination of aerodynamic characteristics of these wings in variant conditions, can be beneficial to plan aircrafts need to fly with high maneuverability in high speeds. This issue becomes important when in supersonic regime, with respect to emerged shock waves and vortices, develop complicated pressure distributions on the wing surface in unsteady state that affect... 

    Measurments of Aerodynamic Forces and Moments Coefficients of Re-entry Vehicle at Supersonic Flow

    , M.Sc. Thesis Sharif University of Technology Ashkian, Omid (Author) ; Soltani, Mohammad Reza (Supervisor)
    Abstract
    Re-entry prediction and control is essential for space research, therefore study of Aerodynamics re-entry is important. Due to the particular configuration of the capsule for thermal protection in the ultrasonic phase capsule becomes unstable at supersonic speeds. The purpose of this study is to establish insight into the behavior of the re-entry in the instability region, for this purpose Fluent software is used to simulate the capsule with Orion configuration in static and dynamic flight. Dynamic simulation was performed using forced oscillation technique to amplitude and frequency of oscillation be examined separately. In zero angle of attack with low frequency, increasing the amplitude... 

    Experimental Investigation of Pressure Distribution on the Surface of a Supercritical Airfoil in Transonic Regime

    , M.Sc. Thesis Sharif University of Technology Talebi, Masoud (Author) ; Soltani, Mohammad Reza (Supervisor)
    Abstract
    Transonic flow study is important due to its vast applications. Supercritical airfoils are designed for transonic flow to postpone drag divergence and reduce the strength of shock. This type of airfoils are chiefly used in modern commercial airplanes because of their low drag in transonic regime and, as a result, reduction in their fuel consumption. Using supercritical airfoils needs accurate investigation of flow field due to several influential factors such as specific geometry, nonlinear nature of flow phenomena, and compressibility effects. However, the availability of experimental and numerical data for supercritical airfoils is less than that of the conventional ones. Thus,... 

    Experimental Investigation of the Effect of Boundary Layer Suction on the Performance of a Supersonic Air Intake

    , M.Sc. Thesis Sharif University of Technology Honaker, Zahra (Author) ; Soltani, Mohammad Reza (Supervisor)
    Abstract
    An extensive wind tunnel tests were conducted on an axisymmetric supersonic inlet at free stream Mach numbers from 1.8 to 2.2, and at different values of mass flow rates. For each test, pressure distributions over the inlet spike was measured and the flow was visualized by means of the shadowgraph system and a high speed camera to obtain main performance characteristics of the inlet during its stable and unstable operations. As the Mach number is increased the pressure recovery is reduced, but maximum value of the mass flow rate is increased. The results of the stable operation of the inlet showed that, variations of the mass flow affects the surface pressure over the entire surface of the... 

    Experimental Investigation of the Effect of the Bleed Slant Angle on the Performance and Stability of a Supersonic Air Intake

    , M.Sc. Thesis Sharif University of Technology Abedi, Mahdi (Author) ; Soltani, Mohammad Reza (Supervisor)
    Abstract
    In the study of supersonic air intakes, two important issues including performance and stability are considered. In these types of intakes, when inlet mass flow rate is reduced to a specified amount, a self-sustained instability called Buzz phenomenon occurs. During this phenomenon, shocks and expansion waves oscillate ahead of the intake that will degrade the performance considerably due to the periodic pressure fluctuations inside the intake. In the current study, a supersonic axisymmetric air intake with mixed compression which has designed for a free stream Mach number of 2.0 has been tested were conducted for free stream Mach numbers of 1.8, 2.0, and 2.2, and the results were analyzed... 

    Mechanism Investigation of Metallic Nanoparticles Interaction with Biological Molecules using Molecular Dynamic Simulation

    , M.Sc. Thesis Sharif University of Technology Soltani, Nima (Author) ; Gholami, Mohammad Reza (Supervisor)
    Abstract
    Amyloid β (Aβ) peptide is believed to be associated with the progression of Alzheimer's disease. One of the main obstacles in developments of therapeutic agents to combat progression of Alzheimer's disease, is the presence of the blood–brain barrier (BBB), which prevents the penetration of the majority of drugs. However, nanoscale objects are able to cross the BBB at low concentrations. Therefore, it is worthwhile to study the interactions of these peptides at the interface of nanomaterials. In this work we have employed molecular dynamics, and weighted histogram analysis methods in order to study the dynamic behavior and affinity of Aβ25-35 peptide on metallic surfaces of different...