Accession Number : ADA338778

Title :   Turbulence Modeling for Free-Surface Flows

Descriptive Note : Final rept. Dec 95-Sep 97

Corporate Author : ERIM INTERNATIONAL INC ANN ARBOR MI

Personal Author(s) : Walker, Dave

PDF Url : ADA338778

Report Date : NOV 1997

Pagination or Media Count : 8

Abstract : The purpose of this effort was to establish the ability of existing engineering turbulence models to predict free-surface turbulent flows, and to lay the groundwork for improved modeling of these flows. The effort had an experimental component, a modeling component, and a instrumentation development component. Data were acquired to initialize and validate Reynolds averaged Navier Stokes (RANS) calculations of free-surface jet flows. This data has been made available to the community via the internet. An existing surface-ship RANS code was adapted to the jet problem and using the acquired data as initial conditions, the evolution of the jets was predicted using a standard k-epsilon turbulence model. This model was evaluated for its ability to predict the features of the free surface jets, and found incapable of predicting the rapid spreading of the jet near the surface. This was traced to its inability to represent the turbulence anisotropy which develops near the free surface in low-Froude-number flows. To support the experimental component of the program, as well as future efforts, a single point, high resolution, laser induced fluorescence surface elevation measurement system was developed, and new laser velocimeter signal processing hardware was acquired. The surface elevation measurement system was successfully completed and is currently being brought on line.

Descriptors :   *TURBULENT FLOW, *FLUID DYNAMICS, LASER INDUCED FLUORESCENCE, HIGH RESOLUTION, NAVIER STOKES EQUATIONS, JET FLOW, REYNOLDS NUMBER, LASER VELOCIMETERS.

Subject Categories : Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE