DocumentCode :
2842431
Title :
Current measurement by lagrangian drifting buoys - Problems and potential
Author :
Vachon, William A.
Author_Institution :
C. S. Draper Laboratory Inc., Cambridge, MA, USA
fYear :
1977
fDate :
17-19 Oct. 1977
Firstpage :
639
Lastpage :
645
Abstract :
This paper discusses the current use of drogued Lagrangian free drifting buoys in terms of the two main problems Which limit their utility - drogue Lagrangian effectiveness (i.e., slippage) and overall drogue survivability. Scale model test data of drogue drag coefficient and behavior are summarized for numerous drogue designs and shapes. The benefits of certain designs are discussed and estimates of drogue slippage as a function of error-inducing drag force are present ed for representative drogues. The measurement of the steady flow horizontal drag coefficient of a full seal window shade drogue is described and compared with the scale model value. The in-situ measurement of the vertical drag coefficient of two full-scale window shade drogues are summarized and estimates made of buoy-drogue vertical interaction forces and conditions for slack line. The results of a full scale, instrumented window shade drogue slippage test are described for the case of a window shade drogue suspended beneath a Nova University minibuoy. The resulting measurement of drogue dynamic behavior and slippage estimates are presented and discussed in relation to the mathematical correctability of current velocity estimates from drogued buoy trajectories.
Keywords :
Current measurement; Drag; Electronic ballasts; Equations; Lagrangian functions; Oceans; Sea measurements; Sea surface; Surface waves; Testing;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
OCEANS '77 Conference Record
Conference_Location :
Los Angeles, CA, USA
Type :
conf
DOI :
10.1109/OCEANS.1977.1154374
Filename :
1154374
Link To Document :
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