Transport phenomena in a proton exchange membrane fuel cell (PEMFC) are highly coupled and complicated by multi-phase flow in the several porous components, electrochemical reaction and the three-dimensional geometry. Naturally, therefore, theoretical work is largely manifested in computational fluid dynamics (CFD). However, the comprehensive three-dimensional (3D) CFD method is often prohibiti...

Heat and vapour convective surface coefficients are required in practically all heat and vapour transport calculations. In building envelope research, such coefficients are often assumed constants for a set of conditions. Heat transfer surface coefficients are often determined using empirical correlations based on measurements of different geometry and flows. Vapour transfer surface coefficient...

Over the last decades, the analysis of transients and accidents in nuclear power plants has been performed by system codes. Though they will remain the analyst’s tool of choice for the foreseeable future, their limitations are also well known. It has been suggested that an improvement in the simulation technology can be obtained by “coupling” system codes with Computational Fluid Dynamics (CFD)...

It is becoming a popular practice for architects and HVAC engineers to simulate airflows in and around buildings by Computational Fluid Dynamics (CFD) methods in order to predict indoor and outdoor environment. However, many CFD programs are crippled by a historically poor and inefficient user interface system, particularly for users with little training in numerical simulation. This investigat...

Model – Contains all information relevant for a CFD simulation like mesh specifications, volume and boundary conditions, initial conditions, needed solver output, etc. Simulation set-ups are defined through classes, relations and attributes in an object oriented approach avoiding issues encountered with history based strategies. Abstract Models are shape and CAD system independent but CFD solve...

Traditional fluid mechanics textbooks are generally written with problem sets comprised of closed, analytical solutions. However, it is recognized that complex flow fields are not easily represented in terms of a closed solution. A tool that allows the student to visualize complex flow phenomena in a virtual environment can significantly enhance the learning experience. Such a visualization too...

The most-widely used approach to explosion consequence analysis is the classical engineering method based on the combination of TNT equivalence, scaled distances and overpressure-based damage levels. This approach rests on established and easily comprehensible elements and permits a fast assessment of explosion consequences. There are however several limitations inherent in this approach. In co...

The modernization of computer technology and commercial computational fluid dynamic (CFD) simulation has given better detailed results as compared to experimental investigation techniques. CFD techniques are widely used in different field due to its flexibility and performance. Evaluation of pipeline erosion is complex phenomenon to solve by numerical arithmetic technique, whereas CFD simulatio...

We present a CFD model that predicts the sedimentation of activated sludge in a full-scale circular secondary clarifier that is equipped with a suction-lift sludge removal system. The axisymmetric single-phase model is developed using the general-purpose CFD solver FLUENT 6, which uses the finite-volume method. A convection-diffusion equation, which is extended to incorporate the sedimentation ...

This paper presents a model-based cell-health-conscious thermal energy management method. An Arrhenius equation-based mathematical model is firstly identified to quantify the effect of temperature on the cell lifetime of a Nickel Metal Hydride (NiMH) battery pack. The cell aging datasets collected under multiple ambient temperatures are applied to extract the Arrhenius equation parameters. The ...