Iranian Journal of Mechanical Engineering Transactions of ISME
Volume:11 Issue: 1, Mar 2010

In the present paper, hybrid differential transform and finite difference method (HDTFD) is applied to solve 2D transient nonlinear straight annular fin equation. For the case of linear heat transfer the results are verified with analytical solution. The effect of different parameters on fin temperature distribution is investigated. Effect of time interval of differential transform on the stability of results has been examined. Results show the excellent capability of HDTFD to solve different engineering problems and also indicate that appropriate selection of differential transform time interval can solve the divergence problem of the method and lead to reduction in computational costs.

The numerical simulation of a Poiseuille flow in a narrow channel using the molecular dynamics simulation (MDS) is performed. Poiseuille flow of liquid Argon in a nanochannel is simulated by embedding the fluid particles in a uniform force field. Density, velocity and Temperature profiles across the channel are investigated. When particles will be inserted into the flow, it is expected that the dynamics of flow will depend on the thermostat chosen. To obtain a more uniform temperature distribution across the channel we use local thermostating near the wall. The obtained results show that velocity profile, slip length and slip velocity depends on the driving force.

The aim of this paper is to give a detailed effect of severalparameters such as step height, Reynolds number, contraction ratio, and temperature difference between the entrance and solid boundaries, of a forward-facing step. An accurate length of separation and reattachment zones are achieved. A finitevolume method (FVM) has been developed to study incompressible flow in a forward-facing step along with artificial compressibility technique. The governing equations are solved by time marching using a fifth-order Runge-Kutta time stepping. The proposed explicit finite volume method uses a new biasing discretization in space. The proposed model reveals that pressure and velocity fields are determinable in a wide range of Reynolds numbers up to 330 without artificial dissipation. The numerical results agree well with the available experimental and numerical data.

In this paper, the static bending, free vibration, and dynamic response of functionally graded piezoelectric beams have been carried out by nite element method under different sets of mechanical, thermal, and electrical loadings. The beam with functionally graded piezoelectric material (FGPM) is assumed to be graded across the thickness with a simple power law distribution in terms of the volume fractions of the constituents. The electric potential is assumed linear across the FGPM beam thickness. The temperature eld is assumed to be of uniform distribution over the beam surface and through the beam thickness. The governing equations are obtained using potential energy and Hamilton's principle based on the Euler-Bernoulli beam theory that includes thermo-piezoelectric effects. The nite element model is derived based on the constitutive equation of piezoelectric material accounting for coupling between the elasticity and the electric effect by two nodes Hermitian beam element. The present nite element is modelled with displacement components and electric potential as nodal degrees of freedom. The temperature eld is calculated by post-computation through the constitutive equation. Results are presented for two-constituent FGPM beam under different mechanical boundary conditions. Numerical results include the inuence of the different power law indexes, the effect of mechanical, thermal, and electrical loadings and the type of in-plane boundary conditions on the deection, stress, natural frequencies, and dynamic response. The numerical results obtained by the present model are in good agreement with the available solutions reported in the literature.