I don't know if I'd call the theory "flawed". Navier-Stokes is a very successful set of equations that is capable of solving real problems as it sets the founda

I don't know if I'd call the theory "flawed". Navier-Stokes is a very successful set of equations that is capable of solving real problems as it sets the foundation for modern day computational fluid dynamics. Any subsequent theories must converge to Navier-Stokes at the regimes where Navier-Stokes is highly successful.