I'm hoping someone with recent experience answers your question. I worked at Carderock in the early 90s, and I can tell you then, computer models worked only for the simplest shapes (only underwater vehicles, nothing on the surface) and were used to narrow down the number of physical models, but the computer models were nowhere close enough to real world to be used in place of extensive scale models.
of course, the phone I am writing this on probably has more processing power than the cray I was using back then!
I'll add that it is not just processing power that is the issue. The Navier Stokes equations for fluid flow (and the related equations) do not have closed form solutions. And even if they did, there are observed flow phenomena that cant be captured. CFD is an area where our mathematical understanding of the problem needs to advance further before we can accurately model in silicon. Some incredibly fascinating problems there - I sometimes wish I had stayed in the field.
I'll add that it is not just processing power that is the issue. The Navier Stokes equations for fluid flow (and the related equations) do not have closed form solutions. And even if they did, there are observed flow phenomena that cant be captured. CFD is an area where our mathematical understanding of the problem needs to advance further before we can accurately model in silicon. Some incredibly fascinating problems there - I sometimes wish I had stayed in the field.