Benjamin deep-ambient front condition
= Benjamin deep-ambient front condition
{c}
{title2=$u_f=\sqrt{2g'h_f}$}
In an ideal <Boussinesq> <gravity current> advancing beneath a much deeper ambient, the local head <Froude number> is $u_f/\sqrt{g'h_f}=\sqrt2$. The ambient must be displaced around the finite-depth head. This differs from the <Saint-Venant dry-front condition>, which neglects ambient inertia. The coefficient belongs to the ideal deep-ambient head model; confinement, mixing and drag can change it.