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Automobile manufacturers and suppliers are under pressure to develop more efficient thermal management systems as fuel consumption and emission regulations become stricter and buyers demand greater comfort and safety. Additionally, engines must be very efficient and windows must deice and defog quickly. These requirements are often in conflict. Moreover, package styling and cost constraints severely limit the design of coolant and air conditioning systems. Simulation-based design and virtual prototyping can ensure greater product performance and quality at reduced development time and cost. The representation of the vehicle thermal management needs a scalable approach with 0-D, 1-D, and 3-D fluid dynamics, multi-body dynamics, 3-D structural analysis, and control unit simulation capabilities. Different combinations and complexities of the simulation tools are required for various phases of the product development process.

Today, thermal management is becoming a more and more important issue in vehicle development. To minimize expenditure and to support rapid development, it is necessary to use efficient simulation tools. With the presented method, precise and detailed thermal analysis of the engine, gearbox, exhaust after treatment, as well as vehicle climate control under stationary and transient driving conditions are possible. It is necessary to use different simulation tools with different modelling depth. With this approach it is possible to cover the entire vehicle thermal management in a scalable manner from 0D to 1D and 3D. However, with the application of different simulation tools the communication between the different software packages (simulation models) must be ensured. This communication is guaranteed by efficient interfaces, which are alsoalso described in this paper.

The de-icing process of the windscreen is a demanding problem in car climatization. In the first stages of the development procedure of air ducts, the numerical simulation plays an important role due to economy of time and money. Unfortunately, the available numerical methods for the generation of the computational grid and the simulation of the de-icing process are very time consuming and are complicated in handling. Therefore normally the quality of the de-icing process is evaluated with simplified simulation procedures or even with measurements late in the design process and necessary modifications are again time and cost consuming. The aim of this paper is to describe new methods for the de-icing simulation that will reduce meshing and calculation time by showing accurate results.

In this paper, the development of numerical droplet wall interaction models for the rainwater management in a car climatization unit has been performed. Moreover the whole rainwater separation process has been simulated by using the new models within a commercial CFD program. To describe the droplet wall interaction processes more accurate new correlations of the occurring phenomena and new numerical models had to be developed. Therefore a new procedure has been proposed. In spite of doing experiments to investigate the processes in droplet wall interactions Direct Numerical Simulation was used to calculate single droplet wall interaction phenomena in detail. By means of the gained results new correlations describing the whole processes for a wide range of geometries and property values could be derived. By using this new correlations numerical models have been developed and implemented in the commercial CFD program SWIFT.