The Energy Budget in Tubular and Planar Type Solid Oxide Fuel Cells Studied through Numerical Simulation

ABSTRACT The energy budget in a tubular and a planar type solid oxide fuel cell (SOFC) is studied based on numerical simulation. By solving the discretized governing equations for flow, temperature, and mass fraction of gas species in the fuel cells, the detailed local parameters determining the local electromotive forces are obtained. The energy flows of electrical power, Joule heating, thermal energy from the entropy change of the electrochemical reaction, as well as the chemical reaction heat by reforming and shift reactions are delineated and compared for the two different types of SOFCs

Inverse Bem Method To Identify Surface Temperatures And Heat Transfer Coefficient Distributions At Inaccessible Surfaces

The purpose of the inverse problem considered in this study is to resolve heat transfer coefficient distributions by solving a steady-state inverse problem. Temperature measurements at interior locations supply the additional information that renders the inverse problem solvable. A regularized quadratic functional is defined to measure the deviation of computed temperatures from the values under current estimates of the heat transfer coefficient distribution at the surface exposed to convective heat transfer. The inverse problem is solved by minimizing this functional using a parallelized genetic algorithm (PGA) as the minimization algorithm and a two-dimensional multi-region boundary element method (BEM) heat conduction code as the field variable solver. Results are presented for a regular rectangular geometry and an irregular geometry representative of a blade trailing edge and demonstrate the success of the approach in retrieving accurate heat transfer coefficient distributions. Copyright © 2005 by ASME

Synthesis and Characterization of Nanocomposites Using the Nanoscale Laser Soldering in Liquid Technique

Abstract We have synthesized Au/CuO and Au/ZnO nanocomposites using the laser soldering technique. The process was carried out by irradiating a solution containing Au-CuO and Au-ZnO nanoparticles using 532 nm laser pulses of 0.1 J/cm 2 continuously for 20 minutes. The beam was focused using a 75 mm focal lens and the laser power near the focal region was estimated to be about 2.4 x 10 12 W/m 2 . Their UV-VIS absorption and transmission were observed and the results indicated that the bandgap energies of the Au/CuO and Au/ZnO are significantly lower than those of pure CuO and ZnO. A theoretical model was developed and the calculation showed that the soldering process was due to the laser melting of the gold nanoparticles and the molten gold got soldered to the ZnO as well as CuO nanoparticles nearby