Turbulence modelling for thermal management of electronic systems

The electronics industry is developing rapidly together with the increasingly complex problem of microelectronic equipment cooling. It has now become necessary for thermal design engineers to consider the problem of equipment cooling at some level. The use of Computational Fluid Dynamics (CFD) for such investigations is fast becoming a powerful and almost essential tool for the design, development and optimisation of engineering applications. However turbulence models remain a key issue when tackling such flow phenomena. The reliability of CFD analysis depends heavily on the turbulence model employed together with the wall functions implemented. In order to resolve the abrupt fluctuations experienced by the turbulent energy and other parameters located at near wall regions and shear layers a particularly fine computational mesh is necessary which inevitably increases the computer storage and run-time requirements. This paper will discuss results from an investigation into the accuract of currently used turbulence models. Also a newly formulated transitional hybrid turbulence model will be introduced with comparisonsaagainst experimental data.

A design pattern for integration of business process management systems

A cross-domain workflow application may be constructed using a standard reference model such as the one by the Workflow Management Coalition (WfMC) [7] but the requirements for this type of application are inherently different from one organization to another. The existing models and systems built around them meet some but not all the requirements from all the organizations involved in a collaborative process. Furthermore the requirements change over time. This makes the applications difficult to develop and distribute. Service Oriented Architecture (SOA) based approaches such as the BPET (Business Process Execution Language) intend to provide a solution but fail to address the problems sufficiently, especially in the situations where the expectations and level of skills of the users (e.g. the participants of the processes) in different organisations are likely to be different. In this paper, we discuss a design pattern that provides a novel approach towards a solution. In the solution, business users can design the applications at a high level of abstraction: the use cases and user interactions; the designs are documented and used, together with the data and events captured later that represents the user interactions with the systems, to feed an intermediate component local to the users -the IFM (InterFace Mapper) -which bridges the gaps between the users and the systems. We discuss the main issues faced in the design and prototyping. The approach alleviates the need for re-programming with the APIs to any back-end service thus easing the development and distribution of the applications

An architectural approach to autonomics and self-management of automotive embedded electronic systems

Embedded electronic systems in vehicles are of rapidly increasing commercial importance for the automotive industry. While current vehicular embedded systems are extremely limited and static, a more dynamic configurable system would greatly simplify the integration work and increase quality of vehicular systems. This brings in features like separation of concerns, customised software configuration for individual vehicles, seamless connectivity, and plug-and-play capability. Furthermore, such a system can also contribute to increased dependability and resource optimization due to its inherent ability to adjust itself dynamically to changes in software, hardware resources, and environment condition. This paper describes the architectural approach to achieving the goals of dynamically self-configuring automotive embedded electronic systems by the EU research project DySCAS. The architecture solution outlined in this paper captures the application and operational contexts, expected features, middleware services, functions and behaviours, as well as the basic mechanisms and technologies. The paper also covers the architecture conceptualization by presenting the rationale, concerning the architecture structuring, control principles, and deployment concept. In this paper, we also present the adopted architecture V&V strategy and discuss some open issues in regards to the industrial acceptance.