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Modelling and Simulation in Engineering
Volume 2012 (2012), Article ID 567864, 8 pages
http://dx.doi.org/10.1155/2012/567864
Research Article

Turbulent and Transitional Modeling of Drag on Oceanographic Measurement Devices

1School of Engineering, University of St. Thomas, 2115 Summit Aveune, St. Paul, MN 55105-1079, USA
2ENEA, UTMAR-OSS, Forte S. Teresa, 19032 Pozzuolo di Lerici, Italy
3Department of Mechanical Engineering, University of Minnesota, 111 Church Street SE, Minneapolis, MN 55455-0111, USA
4Department of Mechanical and Industrial Engineering, University of Illinois at Chicago, Chicago, IL 60607, USA

Received 3 October 2011; Accepted 11 January 2012

Academic Editor: Guan Heng Yeoh

Copyright © 2012 J. P. Abraham et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Computational fluid dynamic techniques have been applied to the determination of drag on oceanographic devices (expendable bathythermographs). Such devices, which are used to monitor changes in ocean heat content, provide information that is dependent on their drag coefficient. Inaccuracies in drag calculations can impact the estimation of ocean heating associated with global warming. Traditionally, ocean-heating information was based on experimental correlations which related the depth of the device to the fall time. The relation of time-depth is provided by a fall-rate equation (FRE). It is known that FRE depths are reasonably accurate for ocean environments that match the experiments from which the correlations were developed. For other situations, use of the FRE may lead to depth errors that preclude XBTs as accurate oceanographic devices. Here, a CFD approach has been taken which provides drag coefficients that are used to predict depths independent of an FRE.