hi to all,
Each engineer have his own rule's of modeling the air fin heat exchanger as rigid element, can any one guide me how to model the air fin heat exchanger 2 pass. I considered above methods can you guide me its correct method of modeling rigid element as per CII.

Thank you for replying.

the tube bundle of these kind of heat exchangers are fixed on one side and guided on the other to the supporting structure. you do not have to model the structure of the equipment itself. you may refer to the mechanical drawing of the equipment to find out the detail information. usually, if the inlets and outlets of the exchanger are at the same side, it would be the fixed side.