Currents, Waves and Hawaiian Reefs
A team of researchers will install instruments off the leeward side of Oahu this summer to collect data that will help engineers improve computerized models that simulate how currents and waves behave when they encounter coral reefs. One application of the work will be to help model how storm waves flood tropical coastlines.
One of the researchers leading the effort is Geno Pawlak, a professor of mechanical and aerospace engineering here at the Jacobs School. Before coming to UC San Diego in 2012, Pawlak was a professor at the University of Hawaii. He has continued to work closely with his former colleagues.
"The applications of our research are broad, since the turbulence associated with drag on the ocean's bed affects how pollutants, nutrients and larvae disperse, as well as temperature," Pawlak said. "From a basic research perspective, we're trying to pin down how much energy is lost by currents and waves over rough surfaces like coral reefs. This energy loss turns out to be an important unknown in developing numerical models for currents and waves, particularly for complex environments like coral reefs."
Divers will deploy instruments on weighted frames on the ocean floor, similar to the three acoustic Doppler velocimeters pictured here, which measure water velocity and pressure. Other instruments will be attached to lines anchored to the ocean bed on one end and to a buoy that floats close to the surface of the water on the other. Researchers also will use an autonomous underwater vehicle from the University of Hawaii to map the ocean's bed and measure water properties, such as temperature.
The work is partially funded by the Office of Naval Research and by the U.S. Army Corps of Engineers.
Seahorse to Robot
Seahorse tails compress to half their original size before permanent damage occurs.
Materials scientists at the Jacobs School are developing a 3D-printed robotic arm inspired by the seahorse's tail. They chose the seahorse for its exceptional flexibility – the animal's tail can be compressed to about half its size before permanent damage occurs. That flexibility is due to the tail's structure, made up of bony, armored plates, which slide past each other.
"The study of natural materials can lead to the creation of new and unique materials and structures inspired by nature that are stronger, tougher, lighter and more flexible," said Joanna McKittrick, a professor of materials science and mechanical engineering who led the effort with graduate student Michael Porter.
The robotic arm would be equipped with muscles made out of polymer and could be used in medical devices, underwater exploration and unmanned bomb detection and detonation. The story attracted the attention of many media outlets, including ABC News, Reuters and Scientific American.
Seahorse video and interviews at bit.ly/11bhc70