College of Engineering and Polymer Science

Date of Last Revision

2021-09-14 17:43:10


Chemical Engineering

Honors Course


Number of Credits


Degree Name

Bachelor of Science

Date of Expected Graduation

Spring 2021


Submarines operate on the basis of a difference in relative densities between of vessel and the surrounding fluid. This principle is based on the force balance that exists between the total buoyancy force and the force due to gravity. Previous work focuses on the neutral buoyancy depths and velocities of object that once submerged, their buoyancy force is a constant along with the force due to gravity. This work aims to better understand how the compression of air at various depths below the surface of the water contribute to the neutral buoyancy depth, velocity of the object as it rises, and the velocity of the object as it sinks through a narrow tube (to demonstrate wall effects and viscous drag). An open-ended cylinder composed of aluminum was utilized to model each scenario with the open-end section being submerged each time. By relating theories such as Archimedes Principle, the monometer equation, and the ideal gas law, a relationship for neutral buoyancy as well as velocity as a function of depth and time were determined. It was found that the diameter influences largely the neutral buoyancy depth as well as the velocity at which it rises due to drag forces. When evaluating a sinking cylinder, the drag force was simplified to be equal to the viscous drag between the cylinder and tube wall. Viscosity and the difference and diameter between the cylinder and tube were the large influences on the velocity in this case. Future work will provide experimental validation.

Research Sponsor

George Chase

First Reader

Bi-min Zhang Newby

Second Reader

Qixin Zhou

Honors Faculty Advisor

Bi-min Zhang Newby

Ethan Davis - Signed Signature Page Honors.pdf (296 kB)
Final Submission Signature Page



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