In this paper, free vibration analysis of magneto-electro-elastic (MEE) cylindrical composite panel reinforced by various distributions of carbon nanotubes (CNTs) considering open and closed circuits boundary conditions based on the first order shear deformation theory (FSDT) is carried out. Carbon nanotubes (CNTs) in Poly-vinylidene fluoride (PVDF) matrix are arranged and different distribution patterns of CNTs including uniform distribution (UD), FG-V, FG-A, FG-X and FG-O are employed. The Young’s and shear moduli are obtained using the extended mixture rule. Also, the material properties of magneto-electric fiber reinforced composite are estimated by mixture rule. By employing energy method and Hamilton’s principle, the equations of motion for cylindrical composite panel reinforced by CNTs are derived. In this paper, the effects of the volume fraction, various distributions of CNTs including uniform and functionally graded (FG) distributions, angle orientation, two elastic foundation parameters, aspect ratio (length-to-thickness ratio), radius-to-thickness ratio, and the multi-physical fields with open and closed circuits boundary conditions on the natural frequency of MEE cylindrical composite panel are considered. These effects play an important role on the natural frequencies. Moreover, the numerical results of this research can be used to manufacturing process design and optimization MEE cylindrical composite panel under multi-physical fields and the previous results can be used in order to prevent the resonance phenomenon.

Double-cyclone in fluidized bed drying is an important equipment which reflects the conditions of drying in HDPE slurry process. Cyclone is an important unite of fluidized bed drying in order to move the solid particles outward to its wall. Therefore, flow pattern created in fluidized bed will affect industrial cyclones installed in dryer for dust removing. Pressure drop of the cyclones is an effective parameter represents the drying behavior. Substantially, geometry of cyclone, inlet flow rate of gas, density and particle size distribution (PSD) can affect the pressure drop value. Fluidized bed hydrodynamic regime is very complex and must be understood to improve fluidized bed operations through theoretical, industrial and CFD study of double-cyclone. Pressure drop is introduced as parameter related to the cyclone efficiency can be calculated with ANSYS Fluent software in the Eulerian-Lagrangian framework with RNG k-ɛ turbulence model used as a mathematical method. Proper pressure drop concluded from industrial experiments and CFD calculation shows good fluidization of HDPE particles in the bed of nitrogen and powder to reach the best fluidized bed situation and suitable quality of HDPE powdery product. Keywords:CFD; HDPE Particles; Double-Cyclone; Pressure Drop. Article History:Received: 28 July 2017Accepted: 01 January 2018 1-IntroductionHDPE Particles of fluid bed drying in the gas entering double-cyclone are subjected to centrifugal forces which move them radially outwards, against the inward flow of gas and towards the inside surface of the cyclone on which the solids separate [1]. The performance of cyclone is in a relationship with its static pressure drop between input and output [2]. The factors affecting the rate of entrainment of solids from a fluidized bed dryer named particle size distribution (PSD), terminal velocity, superficial gas velocity, particle density, gas properties and gas flow regime. Therefore, it is necessary to understand the gas-particle flow and separation characteristics of the cyclone.With computational fluid dynamics (CFD techniques), it is now possible to sufficiently calculate the pressure drop created in cyclone. Fluid flows have been mathematically described by a set of nonlinear and partial differential equations named the continuity and Navier-Stokes equation [3]. ANSYS Fluent solves conservation equations for mass and momentum and additional transport equations are also solved when the flow is turbulent. Different CFD calculation have been successfully applied by employing the related mathematic model to determine the features of gas-solid flow field for cyclones [4,5]. Turbulence models such RNG-based k-ɛ model which was derived using a statistical technique called renormalization group theory is one of the proper models in this field. In Fluent, the Lagrangian discrete phase based partly on the physical properties of dust particles and partly on the mathematical modeling with reasonable assumptions made to describe the particles transport in a fluid medium [6]....

In this article, based on high-order sandwich panel theory and modified strain gradient theory, free vibration analysis of a micro-magneto-electro-elastic sandwich panel with a transversely flexible core and functionally graded carbon nanotube–reinforced nanocomposite face sheets is investigated. Also, the influences of temperature-dependent material properties and various circuit boundary conditions such as open and closed are considered in this study. Carbon nanotubes are arranged in longitudinal direction inside polyvinylidene fluoride matrix with various functionally graded (FG) distributions such as uniform, FG-V, FG-A, FG-X, and FG-O in the face sheets. The generalized rule of mixture is employed to predict mechanical, electrical, magnetic, and thermal properties of micro-sandwich composite panel. The classical shell theory and an elasticity high-order theory are used for the face sheets and the core, respectively. Then, the governing equations of motion are derived using Hamilton’s principle. In this article, the influences of the volume fraction, the various distributions of carbon nanotubes, the multi-physical fields, open- and closed-circuit boundary conditions, the material length scale parameters, different face sheet and core thicknesses, and temperature changes on the natural frequency are investigated, and the obtained results show that these influences play an important role in the natural frequencies and can be used in order to prevent the resonance phenomenon and also for manufacturing process design and optimization of micro-magneto-electro-elastic composite sandwich cylindrical panels.

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