Method for Determining Local Inner and Outer Boundary Layer Length Scales from Drag Measurements in High Reynolds Number Turbulent Flows
Patent application, Filed 20 Dec 2005
DEPARTMENT OF THE NAVY WASHINGTON DC
Pagination or Media Count:
This patent application discloses a method for determining inner and outer boundary layer length scales from a succession of drag measurements of a cylindrical body to estimate flow noise and for computational modeling of the dynamics of towed arrays in a fluid medium. A succession of measurements of the total drag on a cylinder under tow at uniform known conditions i.e., flow speed, fluid density, fluid viscosity, cylindrical body geometry is taken. After each measurement, the cylinder is truncated by a fixed amount, and the process is repeated for the length of the cylinder. The measurements provide a spatially and temporally averaged measure of the mean wall shear stress and momentum thickness, from which the inner and outer length scales can be determined. The inner and outer boundary layer length scales may then be used for estimation of flow noise on towed cylindrical bodies and arrays.
- Theoretical Mathematics
- Submarine Engineering
- Fluid Mechanics