Hi everyone! I will start doing radiation calcualtion, preferrably in the engine compartement of a car, and just want to ask if anyone has any experience in this using any of the cfd-codes fluent or starcd! I suppose we will use a fairly detailed model, 2-5 million cells. Typically we will have a few components that emmits radiation, the turbo and cathalyst etc. Any input is appriciated! Yours Anders

If you are open to exploring other options, please have a look at CFD-ACE+ from CFD Research Corporation. Our home on the web is http://www.cfdrc.com. Please contact me directly at rmm@cfdrc.com for more details.

What are the benefites of CFD-ACE+ compared to Fluent or StarCD.

There are many. The main advantage is that CFD Research Corporation is actively working on providing multi-fideliy, multi-disciplinary computing capabilities.To restrict myself to the subject in the thread, let me state CFD-ACE+ advantages in modeling radiation.

Multi-Fidelity Radiation Modeling: CFD-ACE+ offers

1. Discrete Ordinate Method (DOM) with non-gray banded treatment. CFD-ACE+ has the DOM for longer than others, and experience counts

2. Surface-to-Surface Radiation for extremely quick an inexpensive (yet accurate) radiation modeling. This model is ideal for situations that do not require participating media

3. Monte-Carlo Radiation Model for highest accuracy.

There are more advantages. You are welcome to visit our home on the web at http://www.cfdrc.com. Please contact us direclty if you want details on more specific features.

Engine compartment problem ( under hood problem ) is a highly complex internal flow/ external flow problem. Because of the complex geometry and many objects involved, it is a good idea to simplify the problem or isolate the region of interest one at a time. And the specification of the boundary conditions is also a big unknown. Since it is a coupled external/internal flow problem, it is a good idea to figure out the interface boundary conditions first by measurement or CFD simulation ( still is a difficult task). Otherwise, you will have to compute both the external flow and the internal flow. The other way to do is to treat only the radiation part of the problem. In this case, you need to model the geometry and specify the temperature boundary conditions. This approach would give you the worst condition solution. This maybe is a practical approach. Then later on ,you can include the convection in the simulation.

Anders,

Combining CFD and radiation analysis is one of our strengths. I am with MAYA, we develop both CFD and Thermal simulation tools that are widely used in the electronics, aerospace and automotive industries.

We have done precisely this type of work on several occasions - in fact we are modeling a truck cabin with our software for Renault as we speak. The model combines cabin ventilation flow with solar heating. In the automotive industry Ford, Visteon, Nissan, Renault, Valeo, T&N, and Lucas-Automotive are all using our codes - often for problems that combine radiation and flow analysis. For example, cabins, underhood, undercar, headlamps, heating and ventilation, braking systems, test chambers.

Our applications (ESC and TMG) combine the strength of finite volume based CFD simulation with finite difference based radiation analysis including view factor calculations, environmental and solar heating. ESC is one of the most popular products for electronics cooling simulation today and TMG is a very popular thermal (radiation) code in the space industry. We are familiar with issues like building efficient and accurate radiation models combined with detailed flow models.

If you would like to find out more about us our web site is www.mayahtt.com. We also have local distibutors and engineering support in Sweden that I can put you in touch with if you like.

I would also be happy to send you literature if you would like - I would need your complete coordinates.

Regards,

Arnold Free