Data and computations of a CAD system have been wrapped by a mediator system using CORBA's IIOP Protocol. This allows ad hoc declarative mediator queries to be translated into optimised execution plans sending dynamic IIOP messages to a CAD server. Queries may call computational methods provided only by the CAD system. Dynamic query re-optimisation taking into account what data is currently materialised in the mediator substantially improves the performance compared to static optimisation, despite the added optimisation time. The approach provides both increased flexibility and efficiency compared to the conventional navigational use of CORBA-based CAD interfaces. Furthermore, CAD independences is provided since transparent queries and views can be defined over different CAD systems

The aim of this work is to improve the sharing of Computer Aided Design and Computer Aided Engineering data between different applications by investigating different enabling technologies and developing a integrated design system that make an automated and seamless information exchange for multidisciplinary analysis possible. An embedded approach has been used, which makes the data public with objects that are discrete software components that contain data and are able to manipulate it. The objects could be used directly in different applications. Accordingly the native model is embedded into the application and utilised by the belonging functions. The work has demonstrated how embedded Computer Aided Design data has been used in downstream applications such as structural dynamics and aero-acoustics for exhaust system design.

The work has demonstrated how the conceptual design process can be improved by allowing the seamless and automated sharing of geometry information between a commercial CAD system and a commercial one-dimensional Computational Fluid Dynamics code for the purpose of fluid dynamics analysis of exhaust systems. The driver for this work was the need to carry out conceptual aero-acoustic design of an exhaust system where the simulation model included the intake, engine, and exhaust system. The exhaust system is modeled in the fluid dynamics domain using parameterized building blocks. The integration achieved via the pre-processor developed makes it possible to associate these building blocks with the solid geometry defined in the CAD system and to use this connection to determine their geometric parameters.

The design process in the automotive industry involves several different analysis disciplines. This study focuses on applying multidisciplinary optimization to the design of exhaust systems using commercial software. The software that has been used comprises a solid modelling Mechanical Computer Aided Engineering system, a Finite Element Method solver, a Computational Fluid Dynamics solver and optimization software. An environment for exhaust system design supported by multidisciplinary optimization has been developed. The objective is to present the environmental infrastructure and a method to optimize the aero-acoustic as well as the structural dynamic characteristics of the system