Accession Number:

ADA048038

Title:

Turbulence Levels and Wake Dimensions Behind a Towed Body.

Descriptive Note:

Technical memo.,

Corporate Author:

PENNSYLVANIA STATE UNIV UNIVERSITY PARK APPLIED RESEARCH LAB

Personal Author(s):

Report Date:

1977-09-19

Pagination or Media Count:

24.0

Abstract:

Estimates of the turbulence intensity, its persistence and wake dimensions behind a towed body-of-revolution are presented. Contributors to this turbulence include the drag of the body and its towing strut as well as lift generated by the strut due to any misalignment with the tow direction and secondary vortices from the strutsting intersection. Indications are that if turbulence resulting from body drag were the only consideration, the turbulence would decay to less than 0.10 percent within the time required to return the carriage to the starting point for another run. Calculations that include the drag of the strut show that the waiting time between test runs lengthens slightly. Consideration of disturbances arising from a one degree misalignment of the towing strut results in disturbances of the same order to magnitude as those arising from the drag of the body. Disturbances arising from the secondary vortices have been found to be negligible. An RMS total of all disturbances indicate that a 2-3 minute wait between test runs should be adequate to insure a turbulence level of less than 0.1 percent in the towing basin. Author

Subject Categories:

  • Marine Engineering
  • Fluid Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE