• فهرس المقالات Conveying fluid

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        1 - Nonlinear Vibration of Smart Micro-Tube Conveying Fluid Under Electro-Thermal Fields
        A Ghorbanpour Arani E Haghparast S Amir
        In this study, electro-thermo-mechanical nonlinear vibration and instability of embedded piezoelectric micro-tube is carried out based on nonlocal theory and nonlinear Donnell's shell model. The smart micro-tube made of Poly-vinylidene fluoride (PVDF) is conveying an is أکثر
        In this study, electro-thermo-mechanical nonlinear vibration and instability of embedded piezoelectric micro-tube is carried out based on nonlocal theory and nonlinear Donnell's shell model. The smart micro-tube made of Poly-vinylidene fluoride (PVDF) is conveying an isentropic, incompressible fluid. The detailed parametric study is conducted, focusing on the remarkable effects of mean flow velocity, fluid viscosity, elastic medium modulus, temperature change, imposed electric potential, small scale and aspect ratio on the vibration behavior of the micro-tube. It has been found that stability of the system is strongly dependent on the imposed electric potential. Results of this investigation could be applied for optimum design of sensors and actuators in the sensitive applications. تفاصيل المقالة
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        2 - Nonlinear Instability of Coupled CNTs Conveying Viscous Fluid
        A Ghorbanpour Arani S Amir
        In the present study, nonlinear vibration of coupled carbon nanotubes (CNTs) in presence of surface effect is investigated based on nonlocal Euler-Bernoulli beam (EBB) theory. CNTs are embedded in a visco-elastic medium and placed in the uniform longitudinal magnetic fi أکثر
        In the present study, nonlinear vibration of coupled carbon nanotubes (CNTs) in presence of surface effect is investigated based on nonlocal Euler-Bernoulli beam (EBB) theory. CNTs are embedded in a visco-elastic medium and placed in the uniform longitudinal magnetic field. Using von Kármán geometric nonlinearity and Hamilton’s principle, the nonlinear higher order governing equations are derived. The differential quadrature (DQ) method is applied to obtain the nonlocal frequency of coupled visco-CNTs system. The effects of various parameters such as the longitudinal magnetic field, visco-Pasternak foundation, Knudsen number, surface effect, aspect ratio and velocity of conveying viscous are specified. It is shown that the longitudinal magnetic field is responsible for an up shift in the frequency and an improvement of the instability of coupled system. Results also reveal that the surface effect and internal conveying fluid plays an important role in the instability of nano coupled system. Also, it is found that trend of figures have good agreement with previous researches. It is hoped that the nonlinear results of this work could be used in design and manufacturing of nano/micro mechanical system in advanced nanomechanics applications where in this study the magnetic field is a controller parameter. تفاصيل المقالة
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        3 - Nonlocal Vibration of Embedded Coupled CNTs Conveying Fluid Under Thermo-Magnetic Fields Via Ritz Method
        A Ghorbanpour Arani S Amir
        In this work, nonlocal vibration of double of carbon nanotubes (CNTs) system conveying fluid coupled by visco-Pasternak medium is carried out based on nonlocal elasticity theory where CNTs are placed in uniform temperature change and magnetic field. Considering Euler-Be أکثر
        In this work, nonlocal vibration of double of carbon nanotubes (CNTs) system conveying fluid coupled by visco-Pasternak medium is carried out based on nonlocal elasticity theory where CNTs are placed in uniform temperature change and magnetic field. Considering Euler-Bernoulli beam (EBB) model and Knudsen number, the governing equations of motion are discretized and Ritz method is applied to obtain the frequency of coupled CNTs system. The detailed parametric study is conducted, focusing on the remarkable effects of the Knudsen number, aspect ratio, small scale, thermo-magnetic fields, velocity of conveying fluid and visco-Pasternak medium on the stability of coupled system. The results indicate that magnetic field has significant effect on stability of coupled system. Also, it is found that trend of figures have good agreement with the previous researches. Results of this investigation could be applied for optimum design of nano/micro mechanical devices for controlling stability of coupled systems conveying fluid under thermo-magnetic fields. تفاصيل المقالة