UNCLASSIFIED 
Security, Classification 
DOCUMENT CONTROL DATA-R&D 
Security classification of tithe, body of abstract and indexing: annotation must be entered when the overall report is classified) 
1 ORIGINATING ACTIVITY (Corporate author) 2a. REPORT SECURITY CLASSIFICATION 
UNCLASSIFIED 
2b, GROUP 
Naval Underwater Weapons Research and 
Engineering Station, Newport, R. I. 
7 REPORT TITLE 
Turbulence Measurements in a Tidal Current 
4, DESCRIPTIVE NOTES (Type of report and,inclusive dates) 
5. AUTHOR(S) (First name, middle initial, last name) 
Massey, Alan T. 
6. REPORT DATE 7a. TOTAL NO. OF PAGES 7b, NO. OF REFS 
August 1968 143 23 
8a. CONTRACT OR GRANT NO 9a. ORIGINATOR’S REPORT NUMBER(S) 
. PROJECT NO. TR No. 22 
ib Task Assignment No re 9b. OTHER REPORT NO(S) (Any other numbers that may be assigned 
R360-FR-107/219 1/Ro11-01-01 this report) 
. DISTRIBUTION STATEMENT 
This document has been approved for public release and sale; its 
distribution is unlimited 
SUPPLEMENTARY NOTES 12. SPONSORING MILITARY ACTIVITY 
NUWS - NOSC 
- ABSTRACT 
Measurements were made of the component of turbulent velocity 
along the axis of a 3-knot tidal current 1.5 meters below the water 
surface using a ducted impeller current meter. Values of the one- 
dimensional energy spectra were computed on a digital computer at 
wave numbers from 0 cm-l to 0.157 cm-l. The composite energy 
Spectrum obtained from the individual spectra was of the -5/3 power 
law form predicted by the Kolmogoroff hypothesis for wave numbers 
from 0.01 ecm-! to 0.026 cm-l. At higher wave numbers the energy 
spectrum decreased more rapidly than predicted because of attenuation 
of the turbulent velocity variations caused by the relatively large 
size of the current meter. The average variance for the field of 
turbulence was 55.6 cm2 - sec7-2 +25.0 (standard error), and the 
average rate of energy dissipation by viscosity was estimated using 
the Kolmogoroff hypothesis as 0.84 cm2 - sec73. 
D)D) Oe als) (PRE 1) UNCLASSIFIED 
S/N 0101-807-6811 Security Classification heahaos 
