hi iam madhuri.i am doing a project relatedto swirl generator.so my geometry or domain has 230 small tubes where in air flows inside tubes.the tubes are to be rotated at 100-800 rpm.for this geometry when iam setting moving frame of reference option in fluent to rotate the tubes.the question is should i give rotation to fluid or walls of the tubes or both together.i thought if i give rotation to fluid it would be sufficient.but there is even option for the walls of tube to be stationary or rotating .what should i do to this problem. thanks in advance

Madhuri seela

Hi As I understood that there are 230 small tube in the space and they are rotating,also there is inlet and out let for each tube. and you have a rotating referance frame.

If you give a rotating referance frame in the BC->Fluid-> Moving reference fame and provide the rotation speed this means that the whole fluid domain starts rotating with the rotation you supplied. And if the wall is also rotating with the same rotation as of fluid and i.e they have same rotation rate then give the motion of wall as moving and in motion type relative to cell zone , rotation and then give value as "0" in speed. Does it make sense? If I am not very clear please reply with ur question cleary.