Hi,

I'm modeling heat transfer in an IC engine. I defined heat transfer coefficient in the domain. However I can't specify the HTC for the interface I created for the cylinder volume and as a result the in-cylinder temperature is very high. The Heat Transfer option gives only 'adiabatic' choice to work on. I wish to specify the 'interface' cylinder wall as 'permitting heat transfer to outside', with the outside temperature I specified as atmospheric temperature. Please help me on this.

Regards

George

Hi,

Why do you want to define a HTC on an interface? Why is the cylinder wall an interface? Are you modelling the cylinder barrel and coolant?

If you are modelling the cylinder barrel then you don't specify the HTC as it is evaluated as part of the interface boundary.

Some bedtime reading for you: http://hdl.handle.net/2100/248

Glenn Horrocks

Hi Glenn,

Thanks for your reply.

In my case I'm modeling IC engine with ports, were the ports mesh remains stationary and the cylinder mesh moves. So I think I need to create interface b/w inlet & exhaust port domains and the cylinder domain. Datz the reason for this interface, to allow relative motion b/w domains.

During combustion the cylinder and included substance need to transfer heat through the cylinder wall, otherwise this is going to be an adiabatic condition I suppose. Right now I have high levels of temperature inside the engine after energy release which is an undesirable situation. I'm not able to specify the heat transfer through this cylinder interface.(the whole cylinder periphery is specified as interface in this case). Could you give me any suggestions to solve this?

George

Hi,

I am not sure a GGI connecting a moving mesh region to a solid region is supported. I don't think it is supported. If it is being treated as adiabatic then there is no interface.

Glenn Horrocks

Hi Glenn,

Thanks for your reply.

I had a talk with some Ansys technicians, and they told me that the facility to allow heat transfer through an interface wall may be available in the forthcoming version of Ansys CFX which will be V12.0. Currently as you mentioned, it is not supported in V11.0. So I'm trying some other means to fix this problem.

George.