Author(s): Camilo E. Pinilla; Vincent H. Chu
Linked Author(s): Vincent H. Chu, Camilo Pinilla
Keywords: No Keywords
Abstract: The transverse shear instabilities of a one-layer stratified flow are analyzed as a model of coastal currents and of the atmospheric winds across the thermal-andmoisture fronts. The shear flows in nature are driven by gravity and governed approximately by the shallow water equations. Direct numerical simulations were conducted for the base flow in the form of a jet. The growth rate of the instabilities is determined for a range of convective Froude number Fr C from 0 to 4. The simulations have identified radiation damping as a factor of influence on the instability. The convective Froude number correlated the energy lost due to radiation damping. A fraction of available energy produced by the shear flow is lost due the radiation of internal waves at supercritical flow. This radiation in gravity stratified flow, and its dependence on the convective Froude number, is analogous to the Mach-number effect in compressible flow.
Year: 2009