Turbulent flow over a wavy surface: Stratified case

Stably stratified turbulent flow over wavy terrain is investigated using large‐eddy simulation for laboratory‐scale domains. Basic near‐wall turbulence structure and production mechanisms appear similar to the neutral case, though dampened. The state of turbulence in the stratified fluid is analyzed by graphing the relationships between key nondimensional parameters. A shifting and smearing of the curve of flux Richardson number Rif versus turbulent Froude number Frt caused by the wavy boundary (compared with a flat boundary) demonstrates the higher level of turbulence near the wavy wall and shows strong mixing in the detached shear layer over the trough. The relationship describing the state of turbulence in a stratifed fluid given by Ivey and Imberger [1991] is approximately satisfied. Conditional sampling is used to analyze the nature of Reynolds stress events.