URI studying underwater booms

UNDER PRESSURE: University of Rhode Island mechanical engineering students, from left: Sachin Gupta, Christopher Shillings and Payam Fahr, ensure that an implosion experiment is ready to start. The implosion vessel was purchased with a grant from the Office of Naval Research. / COURTESY JOHN PETERSON
UNDER PRESSURE: University of Rhode Island mechanical engineering students, from left: Sachin Gupta, Christopher Shillings and Payam Fahr, ensure that an implosion experiment is ready to start. The implosion vessel was purchased with a grant from the Office of Naval Research. / COURTESY JOHN PETERSON

Two projects to study implosion have brought $840,000 in funding from the Office of Naval Research to the University of Rhode Island.
The funding includes a $225,000 grant from the Defense University Research Instrumentation Program that was used to purchase an implosion testing vessel that is 7 feet in diameter, stands 7 feet tall and “looks a bit like a cross between a pressure cooker and a space station module,” said URI spokesman Todd McLeish.
The experimental vessel is designed to simulate pressures of up to a half-mile deep in the ocean so scientists can study underwater shockwaves and the stresses, velocities and other dynamic phenomena caused by explosions and implosions, McLeish said.
“The $225,000 grant comes with the stipulation the vessel be used for projects for the Office of Naval Research,” said URI professor of mechanical engineering Arun Shukla.
In addition to covering the cost of the vessel, the funding is for two projects being done in collaboration with the Naval Undersea Warfare Center in Newport.
The Office of Naval Research awarded URI $305,000 for a three-year implosion research project on metallic materials, said Shukla, adding that URI was awarded an additional $310,000 for implosion research on composite materials.
“For a long time, the Navy has used metals for their ships, for their submarines and for other containers, maybe for launching weapons, but the use of composite materials is very new,” Shukla said.
Composite materials being used in the research, such as glass fiber and reinforced polymers, are similar to materials used for the boat industry in Rhode Island, said Shukla.
It’s not just the project on composite materials that’s leading-edge research.
“For the metals part, we are also on the leading edge in the types of problems we are exploring,” Shukla said. “These problems have not been studied by others in the past.”
The research projects are valuable to the Navy because they can help shed light on and prevent accidents like one that happened several decades ago, Shukla said.
In April 1963, the U.S. Navy nuclear attack submarine USS Thresher was on deep-dive trials 220 miles east of Cape Cod, according to the Naval History & Heritage Command website. The Navy determined that the submarine probably sunk because of a piping failure, the subsequent loss of power and the inability to blow ballast tanks rapidly enough to avoid sinking, according to the website. All of the 129 officers, crewmen and civilian technicians were lost in the accident.
When an accident like that happens, for example, when a submarine develops a leak, sinks and reaches a critical depth, it implodes, said Shukla.
The current requirements relating to implosion are “costly in terms of dollars and weight added to the boat,” Leblanc said.
“The purpose of the research is to save money for the Navy in the design and testing and to save weight in underwater structures,” said Stephen Turner, a civilian who heads the Ranges Engineering and Analysis Department at the Naval Undersea Warfare Center.
The project with URI is for basic research on implosion that can apply not just to submarines, but to a wide variety of underwater devices the Navy might submerge, for example, sensors, Turner said.
The research also has potential commercial applications, such as piping systems for oil drilling, said Turner.
Others who do underwater work such as deep diving could benefit from the research, said Shukla.
The collaboration between URI and the Navy is valuable for both institutions and for Rhode Island, said Shukla.
“We do the experiments in the lab and some of the theoretical work on understanding the research results,” said Shukla. “The Navy does the computer simulations. The Navy has such outstanding facilities for computational work.
“These projects are useful for the Navy and for industry and also in creating a highly-trained workforce,” said Shukla.
Shukla has been at URI since 1981, and it is about three decades since he established his Dynamic Photomechanics Lab. Twenty-four of his students have gone on to work for the government, some for the Navy in Rhode Island.
Three of Shukla’s Ph.D students and one undergraduate student are assisting with the implosion research projects, he said. One of the Ph.D students is currently a full-time Navy employee.
“We use high-speed imaging to see how things are happening and couple it with optical techniques,” said Shukla. “For example, we might want to know in a millionth-of-an-inch how fast something is moving.
“Our first camera cost half-a-million dollars. The National Science Foundation gave us money to buy that first camera about 15 years ago,” said Shukla. “The Navy gave us another grant … to buy three more cameras to do research.
“These cameras are mind-boggling,” said Shukla. “The fastest one we have can take two hundred million images in one second.” •

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