A new development and interpretation of the Navier–Stokes fluid which reveals why the “Stokes assumption” is inapt

In this short paper I present an alternate way of describing fluids in general, and the Navier–Stokes fluid in particular, from a phenomenological point of view, that shows clearly that the putative assumption conjectured by Stokes is not a reasonable assumption. I also show that the procedure presented here is more suited for incorporating constraints such as that of incompressibility, as well as having other advantages. The approach also helps to pinpoint several serious errors in the justifications that are provided in classical texts for the development of the Navier–Stokes model. Finally, from the point of view of the role that causality plays in Newtonian mechanics, the approach suggested is the preferable approach.

► In this paper a new approach is presented for the development of constitutive relations for fluids.
► Using this approach the Navier–Stokes equation is arrived at.
► The approach concludes that an assumption that Stokes suggested is invalid.