But a new computer program and method of analysis by University of Michigan researchers makes it easy to see that a series of smaller waves—a situation much more likely to occur—could be just as dangerous.
"Like the Edmund Fitzgerald that sank in Michigan in 1975, many of the casualties that happen occur in circumstances that aren't completely understood, and therefore they are difficult to design for," said Armin Troesch, professor of naval architecture and marine engineering. "This analysis method and program gives ship designers a clearer picture of what they're up against."
Troesch and doctoral candidate Laura Alford will present a paper on their findings Oct. 2 at the International Symposium on Practical Design of Ships and Other Floating Structures, also known as PRADS 2007.
Today's ship design computer modeling programs are a lot like real life, in that they go from cause to effect. A scientist tells the computer what type of environmental conditions to simulate, asking, in essence, "What would waves like this do to this ship?" The computer answers with how the boat is likely to perform.
Alford and Troesch's method goes backwards, from effect to cause. To use their program, a scientist enters a particular ship response, perhaps the worst case scenario. The question this time is more like, "What are the possible wave configurations that could make this ship experience the worst case scenario?" The computer answers with a list of water conditions.
What struck the researchers when they performed their analysis was that quite often, the biggest ship response is not caused by the biggest waves. Wave height is only one contributing factor. Others are wave grouping, wave period (the amount of time between wave crests), and wave direction.
"In a lot of cases, you could have a rare response, but when we looked at just the wave heights that caused that response, we found they're not so rare," Alford said. "This is about operational conditions and what you can be safely sailing in. The safe wave height might be lower than we thought."
This new method is much faster than current simulations. Computational fluid dynamics modeling in use now works by subjecting the virtual ship to random waves. This method is extremely computationally intensive and a ship designer would have to go through months of data to pinpoint the worst case scenario.
Alford and Troesch's program and method of analysis takes about an hour. And it gives multiple possible wave configurations that could have statistically caused the end result.There's an outcry in the shipping industry for advanced ship concepts, including designs with more than one hull, Troesch said. But because ships are so large and expensive to build, prototypes are uncommon. This new method is meant to be used in the early stages of design to rule out problematic architectures. And it is expected to help spur innovation.
A majority of international goods are still transported by ship, Troesch said.
The paper is called "A Methodology for Creating Design Ship Responses."
The University of Michigan College of Engineering is ranked among the top engineering schools in the country. Michigan Engineering boasts one of the largest engineering research budgets of any public university, at more than $130 million. Michigan Engineering has 11 departments and an NSF Engineering Research Centers. Within those departments and the center, there is a special emphasis on research in three emerging areas: nanotechnology and integrated icrosystems; cellular and molecular biotechnology; and information technology. Michigan Engineering is seeking to raise $110 million for capital building projects and program support in these areas to further research discovery. Michigan Engineering's goal is to advance academic scholarship and market cutting-edge research to improve public health and well-being.
Nicole Casal Moore | EurekAlert!
Massive impact crater from a kilometer-wide iron meteorite discovered in Greenland
15.11.2018 | Faculty of Science - University of Copenhagen
The unintended consequences of dams and reservoirs
14.11.2018 | Uppsala University
Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.
Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...
Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.
In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...
On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.
When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure
Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...
Physicists at ETH Zurich demonstrate how errors that occur during the manipulation of quantum system can be monitored and corrected on the fly
The field of quantum computation has seen tremendous progress in recent years. Bit by bit, quantum devices start to challenge conventional computers, at least...
09.11.2018 | Event News
06.11.2018 | Event News
23.10.2018 | Event News
15.11.2018 | Earth Sciences
15.11.2018 | Physics and Astronomy
15.11.2018 | Physics and Astronomy