Creation of nonlinear density gradients for use in internal wave research

A method was developed to create a nonlinear density gradient in a tank of water. Such gradients are useful for studying internal waves, an ocean phenomenon that plays an important role in climate and ocean circulation. The method was developed by expanding on the two-tank system currently used to create linear density gradients. A mathematical model of the two-tank system was used and a Matlab script was written to solve the model for the required flow rates in the system given a desired density gradient. The method was tested by creating three different density gradients: a linear gradient, a hyperbolic gradient, and a two-layer gradient. It was discovered that for a two-layer gradient the flow rates for each layer must be calculated independently of each other, because of problems integrating over a density gradient with a non-continuous slope. It was also discovered that the system failed at very low flow rates; insufficient mixing in the two-tank system led to gradients weaker than expected. Overall, the measured gradients matched up well with the expected gradients, and it was concluded that the system can successfully produce nonlinear density gradients.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Mechanical Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2007

Author dc:creator

• Harris, Victoria Siân

Advisor dc:contributor.advisor

• Thomas Peacock.

• Mechanical Engineering.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/40437

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/40437