Leonard Collum
Subscriber

"Hi Arba, please refer to this ANSYS FLUENT–Operation would result in time shooter 2 manifold bodies
Non-manifold means you're creating an impossible geometry, typically with a surface of zero area. Also, try to extract fluid volume via SpaceClaim."

It turned out that my geometry was in the case of impossible geometry. So, It can't be a boolean. Thanks for your useful information.