Profiling the water column to achieve both high vertical and horizontal resolution from a moving vessel in deep water is difficult. All current solutions, such as CTD tow-yo?s, moving vessel profilers and undulating tow bodies are significantly limited by ship speed or water depth, especially beyond 100 meters. As a consequence it is difficult to obtain oceanographic sections with sufficient resolution to identify many relevant scales.
The PI?s request funding to design and build a versatile depth-independent system using flying vehicles which slide up and down a towed wire in a controlled manner using the lift created by wing foils. Prior work has demonstrated the viability of the proposed concept. Scale model tests have shown a wide range of achievable glide slopes for cable angles between vertical and 45 degrees. The wing foils provide a novel low power method of propulsion along the cable, in similar fashion to a sailboat sailing up wind, that utilizes the free stream velocity of the wire moving through the water. Tests have also demonstrated effective isolation of cable strum vibration from the towed flyer body using several spring mount concepts.
The proposed 1000 meter system will consist of two cable flying vehicles carrying sensors, and a depressor weight to keep the cable tight. The flyers will be streamlined, battery powered vehicles containing packaged electronics, a wing motor actuator, flotation, acoustic communications hardware, and a passively articulating tail fin. Data collection, logging and control will be achieved by a small microprocessor and peripheral circuitry. The proposed vehicles will support CTD sensors and have payload capacity for a variety of other sensors, such as fluorometers, dissolved gas and turbidity, applicable for a wide range of studies.
Broader Impacts:
Using of this project as an undergraduate engineering project makes a lot of sense. It will develop potentially important technology and methodologies; involves several different disciplines of engineering, science, project management, at-sea operations, etc.; is a big enough project to require a team effort over several phases and has a reasonable scope to be manageable. This profiling system has broad application in both coastal and deep-water oceanography, and by having a flexible scientific payload capability on each self-recording flyer vehicle, should be capable of supporting a range of physical, chemical and biological sampling systems.
