For a wing, the flow domain is not mandatory to be a spherical domain. You can even consider a cubical domain as well to analyse the flow field. It's easier to mesh the cubical domain than the spherical.
However, Hexa meshing for spherical domain requires an advanced level expertise. You may refer to the below video for Meshing of spherical domain in ICEM CFD.
Sampath Emani Thank you so much for answering my question . Actually I need to rotate the wing while flow is passing through it , I guess it is only possible when a spherical domain is used .