Flowmeter: A Hand Crafted Surface Current Measurement Device
The problem that faced the design team was to develop and manufacture a durable, inexpensive device that consistently and accurately measured surface currents. This device was to be utilized as a teaching aid and targeted towards educational organizations.
The previous design employed a horizontal savonius paddle. It was fairly inexpensive and somewhat compact. However, it lacked in overall durability and was not stable at high speeds. The low visibility of the paddlewheel created problems with accuracy that needed to be improved.
In order to improve the previous design and develop a better device, it was necessary to specify the goals of the project. The new design needed to have the ability to measure consistently and be manufactured economically. Improvements needed to be made on overall durability, measurement accuracy and resolution, high-speed measurement capability, and visibility of the display. Furthermore, it was necessary to target a younger student market and in turn increase the visibility of the paddlewheel to facilitate students' understanding of how the device worked.
The first step was to test the preliminary design. It was observed in a tow tank, and the necessary improvements were noted. Material selection, paddlewheel design, pontoon design, speed sensor selection, and overall protection from wind interference and any type of impact were the main areas of interest. The paddlewheel and pontoon designs were empirically chosen.
When the final design was chosen, necessary calculations were performed to determine the sizes of specific parts. Detailed drawings were generated in order to produce the unit. Manufacturing the design was an important aspect of the project that the team was involved in. Finally, tests were performed to calibrate the unit to determine the threshold speed and discover if a maximum speed of two knots could be obtained.
Available from the National Sea Grant Library (use NHU number to search) or NH Sea Grant
- Flowmeter. A hand crafted surface current measurement device (1998). J. Parker Lewis, Michael Kobaly and Jeffrey Pearl. Advisor: Franz Anderson.