Churchill–Bernstein equation
In convective heat transfer, the Churchill–Bernstein equation is used to estimate the surface averaged Nusselt number for a cylinder in cross flow at various velocities. The need for the equation arises from the inability to solve the Navier–Stokes equations in the turbulent flow regime, even for a Newtonian fluid.
Source: Wikipedia — Churchill–Bernstein equation (CC BY-SA 4.0)