Do you mean with the first sentence to pic Fluid for the contours rather than Internal? (I don’t know why there is such high velocity under the bridge slab deck)

In this case I am not considering the supports as I am analysing middle span sections. (The four thin small lines below the deck are steel girders).

Does Fluent consider buoyancy?

What do you mean with “You may need to resolve the mesh near the free surface,” I used a BOI for the interfase

My main focus is to get drag and lift forces and coefficients.

Then, Residuals & reports are like this even though is a steady state?