A mathematical model to describe the detailed three-dimensional transient heat transfer process in friction stir welding (FSW) is presented. This work is both theoretical and experimental. An explicit central diVerential scheme is used in solving the control equations, the heat transfer phenomena during the tool penetrating, the welding and the tool-removing periods that are studied dynamically...

This paper studies unsteady laminar flow of dusty conducting fluid between parallel porous plates with temperature dependent viscosity. The fluid is acted upon by a constant pressure gradient and an external uniform magnetic field is applied perpendicular to the plates. The parallel plates are assumed to be porous and subjected to a uniform suction from above and injection from below. The visco...

We present a new immersed method for solving conjugate heat transfer and fluid-solid interactions (FSI). It is based on the use of Non Uniform Rational B-Splines (NURBS) to compute the distance function ans thus representing the immersed solids inside the computational domain. Combined with anisotropic mesh adaptation and stabilized Finite Elements Method (FEM), it allows a novel, efficient and...

Abstract: Elliptic interface problems arise in various areas of science and engineering. The steady state heat conduction in layered bodies is one of the largest areas of application of elliptic interface problems. In this paper, a mathematical model and solution of a one dimensional elliptic interface problem which represents a steady state heat conduction problem in composite medium have been...

Compared with the conventional manufacturing of aluminum sheet metal, the forming of so called Tailored Heat Treated Blanks (THTB) enables the production of complex aluminum sheet metal parts [1], [2]. The reasons for the lower forming behavior of aluminum alloys are well founded in the material properties. Especially smaller values for uniform elongation (< 30 %) and vertical anisotropy (< 1) ...

An attempt has been made to study the heat and mass transfer effect in a boundary layer flow through porous medium of an electrically conducting viscoelastic fluid over a shrinking sheet subject to transverse magnetic field in the presence of heat source. Effects of radiation, viscous dissipation, and uniform heat sink on the heat transfer have been considered. The method of solution involves s...

Visual acuity, phoria, stereopsis, and contrast sensitivity were assessed over 6 h of continued exposure to combinations of atropine (2 mg) and 2-PAM chloride (600 mg), severe heat/humidity (95 degrees F (35 degrees C); 60% RH), and wearing either the U.S. Army battle dress uniform (BDU) or the BDU and the impermeable chemical protective clothing (MOPP-IV). Subjects were able to complete all 6 ...

This paper presents the numerical analysis of a Miniature-Scale Refrigeration System (MSRS) for electronics cooling. The system consists of a simulated electronic chip attached to a microchannel cold plate evaporator, a compressor, a microchannel condenser, and an expansion device. The system uses R-134a as the refrigerant. A copper block heater is designed to simulate the heat generation of an...

Thermal diffusivity values of molten germanium and silicon were measured by a laser flash method. Simple but useful sample cell systems were developed to keep the molten germanium and silicon shape uniform for a given thickness. In the present experimental condition, it is necessary to consider the effect of not only the radiative heat loss but also the conductive heat loss at the interface bet...

We shall describe the diffusion of heat energy through a long thin rod G with uniform cross section S. As before, we identify G with the open interval (a, b), and we assume the rod is perfectly insulated along its length. Let u(x, t) denote the temperature within the rod at a point x ∈ G and at time t > 0. Our previous experience shows that the heat flux q(x, t) at the point x, i.e., the flow r...