[Book review] Book of Shadows

Tony Mann provides a review of the book: Simon Biggs, Book of Shadows, Ellipsis (Electric Art Series: 1), 64pp. with CD-Rom, 1996, ISBN 1-899858-156. £15. [Needs Multimedia PC (Windows, 486 or Pentium processor), or Macintosh (68040 or PowerPC)]

Experience of using a CFD code for estimating the noise generated by gusts along the sun-roof of a car

The problem to be examined here is the fluctuating pressure distribution along the open cavity of the sun-roof at the top of a car compartment due to gusts passing over the sun-roof. The aim of this test is to investigate the capability of a typical commercial CFD package, PHOENICS, in recognising pressure fluctuations occurring in an important automotive industrial problem. In particular to examine the accuracy of transporting pulsatory gusts traveling along the main flow through the use of finite volume methods with higher order schemes in the numercial solutins of the unsteady compressible Navier-Stokes equations. The Helmholtz equation is used to solve the sound distribution inside the car compartment, resulting from the externally induced fluctuations.

Can hypermedia aided learning (HAL) deliver?

This paper presents the results of a research project aimed at evaluating (HAL) as a mode of course delivery. More specifically the paper will deal with: • Developing a hypermedia courseware for students studying research methods; and • Evaluating hypermedia courseware as a method of delivery against traditional methods. This paper concentrates on pedagogical issues regarding computer aided learning and reports that this research gives tentative indications that hypermedia based learning (either through CD-ROM or the, as means of course delivery could be as effective as traditional modes of course delivery.

Turbulence model performance in continuous casting simulations

This paper concerns the development and validation (using an oil/water system) of a finite volume computer model of the continuous casting process for steel flat products. The emphasis is on hydrodynamic aspects and in particular the dynamic behaviour of the metal/slag interface. Instability and wave action encourage the entrainment of inclusions into the melt affecting product quality. To track the interface between oil and water a new implicit algorithm was developed, called the Counter Diffusion Method. To prevent excessive damping, a time-filtered version of the k-e model, was found necessary, with appropriate density stratification terms representing interface turbulence damping.

The effects of thermo-electrically induced convection in alloy solidification

The effects of a constant uniform magnetic field on thermoelectric currents during dendritic solidification were investigated using a 2-dimensional enthalpy based numerical model. Using an approximation of the dendrite growing in free space it was found that the resulting Lorentz force generates a circulating flow influencing the solidification pattern. As the magnetic field strength increases it was found that secondary growth on the clockwise side of the primary arm of the dendrite was encouraged, while the anticlockwise side is suppressed due to a reduction in local free energy. The preferred direction of growth rotated in the clockwise sense under an anti-clockwise flow for both the binary alloy and pure material. The tip velociy is significantly increased compared to growth in stagnant flow. This is due to a small recirculation that follows the tip of the dendrite; bringing in colder liquid and lower concentrations of solute. The recirculation being not normally incident on the tip is most likely the cause for the rotation. Grain growth consisting of multiple seeds with the same anisotropy growing in the same plane, gives a competition to release latent heat resulting in stunted growth. The initial growth for each dendrite is very similar to the single seed cases indicating that dendrites must become before the thermoelectric interactions are significant.

Optimizing the reliability of power electronics module isolation substrates

Optimal design of a power electronics module isolation substrate is assessed using a combination of finite element structural mechanics analysis and response surface optimisation technique. Primary failure modes in power electronics modules include the loss of structural integrity in the ceramic substrate materials due to stresses induced through thermal cycling. Analysis of the influence of ceramic substrate design parameters is undertaken using a design of experiments approach. Finite element analysis is used to determine the stress distribution for each design, and the results are used to construct a quadratic response surface function. A particle swarm optimisation algorithm is then used to determine the optimal substrate design. Analysis of response surface function gradients is used to perform sensitivity analysis and develop isolation substrate design rules. The influence of design uncertainties introduced through manufacturing tolerances is assessed using a Monte-Carlo algorithm, resulting in a stress distribution histogram. The probability of failure caused by the violation of design constraints has been analyzed. Six geometric design parameters are considered in this work and the most important design parameters have been identified. Overall analysis results can be used to enhance the design and reliability of the component.

Concise introduction to image processing using C++

A Concise Intro to Image Processing using C++ presents state-of-the-art image processing methodology, including current industrial practices for image compression, image de-noising methods based on partial differential equations, and new image compression methods such as fractal image compression and wavelet compression. It includes elementary concepts of image processing and related fundamental tools with coding examples as well as exercises. With a particular emphasis on illustrating fractal and wavelet compression algorithms, the text covers image segmentation, object recognition, and morphology. An accompanying CD-ROM contains code for all algorithms.