I would like to understand the relationship between the drag force of an object in a fluid and the microscopic interactions between the object and the fluid particles.
Specifically, I would like to understand the relation between drag and shear/normal stress. In the following post, a formula for drag $D$ was provided: https://www.physicsforums.com/threads/drag-equation-derivation.64110/#post-468849
However, there is no documentation on the assumptions and derivation of the equation. Can someone provide a rigorous reference for this equation (or a more accurate version)?