Intrusion into a stratified fluid

Abstract

Preliminary measurements have been made of the debouching of homogeneous fluid from a broad source at its equilibrium depth into a linearly stratified tank of salt water. With c the velocity of the nose of the intrusion, h its half-thickness near the source, N the environmental buoyancy frequency and v the kinematic viscosity of the fluid, it is shown for 100 [lsim ] Re ≡ 2ch/ν [lsim ] 500 that the intrusion becomes practically steady under an inertia-buoyancy balance. The internal Froude number Fr = c/Nh is shown to be of order unity. Forward-propagating disturbances and the ends of the tank are inferred to play an important part in the flow.