TURBULENT STRUCTURE IN FREE-SURFACE JET FLOWS

This paper examines the evolution jet beneath a free surface using a three-component laser velocimeter. Reynolds- and Froude- number effects in the interaction of the jet with the free surface are identified. At low Froude number, the anisotropy of the turbulence near the free surface is increased. The outward velocity near the surface, which gives rise to a surface-current layer, is larger at low Froude number. An increase in Reynolds number further increases the magnitude of this outward velocity. At low Froude number, the mean velocity profiles exhibit spatial variations which may be due to coherent vorticity attached to the free surface. These variations are absent at high Froude number, probably due to changes in vorticity/free-surface interaction, caused by the larger surface deflections. These changes in vorticity/free-surface interaction may also result in the smaller outward velocity observed at high Froude number. Near the free surface, the high-mean-shear regions of the flow exhibit locally elevated Reynolds shear stress which contributes to surface current.

• Supplemental Notes:
  • Naval Hydrodynamics, 19th Symposium; 23-28 August 1992; Seoul, Korea. Sponsored by Office of Naval Research, USA; National Research Council, USA; and Soc Naval Architects of Korea. Procs. Publ by National Academy Press, Washington, DC, USA, 1994. Session IX, p 523 [16 p, 13 ref, 1 tab, 38 fig]
• Authors:
  • Walker, D
  • Chen, C Y J
  • Willmarth, W
• Publication Date: 1994

Language

• English

Subject/Index Terms

• TRT Terms: Flow; Free surface; Jet engines; Turbulence
• Candidate Terms: Turbulent flow
• Old TRIS Terms: Jet flow
• Subject Areas: Marine Transportation; Vehicles and Equipment;

Filing Info

• Accession Number: 00710238
• Record Type: Publication
• Source Agency: British Maritime Technology
• Files: TRIS
• Created Date: Aug 14 1995 12:00AM