Airline cabin environment research could make the air up there better
"Contagion" is just a thriller of a movie but its premise - a deadly disease spread around the world by airline passengers - is no fiction, as experience with SARS and the H1N1 flu virus illustrate.
That’s one reason Purdue mechanical engineering Professor Qingyan Chen and his students are looking at aircraft environmental control systems with an eye to making them less apt to circulate airborne contaminants, as well making the systems less of a drain on fuel consumption.
Chen, principal investigator for the Air Transportation Center of Excellence for Airline Cabin Environment at Purdue, combines physical experiments and intensive computer modeling in his lab’s research, aided by the Hansen community cluster.
"Our research involves the solution of very complex equations and then we do iterations, which is why it takes so much computing power," says Chen, whose models not only consider the three-dimensional nature of air circulation in spaces like airline cabins but often a fourth dimension, changes over time.
Chen is particularly interested in enclosed environments like the cabins of airliners or the interior of buildings; how we treat those environments to make them livable and comfortable; and how the systems involved can be improved, promote energy efficiency and save money.
For example, while airliners generally compress air from their engines, treat it and use it to keep the cabin comfortable, Boeing’s new 787 Dreamliner has a separate compression system especially for the purpose, which increases engine efficiency as well as reduces the possibility of contaminants entering the cabin atmosphere from the engine. Projections show that if all aircraft used such a system, it could save millions of tons of expensive jet fuel a year, Chen says.
Likewise, buildings could be designed to take better advantage of the temperature and the light outside to reduce heating, cooling and lighting energy use and costs inside, Chen says. In blustery Chicago, for instance, a building or group of buildings might be designed to block the icy winter wind from one direction, making them easier to heat, while catching the breeze in the summer from another direction to keep them cooler.
Chen, who also has used the Coates and Steele community clusters, employs computational fluid dynamics to simulate such systems and search for optimal designs. His lab uses Fluent, the industrial-strength software for fluid dynamics modeling, from airflow over an aircraft wing to blood flow in the body, and also develops its own codes. The research looks at such things as air circulation, distribution of air quality and the circulation of particulates. Long jobs, even on a machine like Hansen, can take a week. The work also generates large amounts of data that has to be juggled in the process.
In a way, Chen says he's after the same thing as computer game designers and the creators of computer-generated special effects for movies, who now use fluid dynamics to create super-real effects like fire. The more detailed his research simulations, the higher their resolution, the better the understanding of the science and its applications.
The Community Cluster Program provides needed computational resources and relieves his lab of the time and effort that would be involved in operating its own high-performance computing system, Chen says.
He also likes the sharing aspect of the program. Faculty partners always have ready access to their share of a cluster, but they also have the opportunity to tap idle capacity from their peers if needed for particularly demanding computations.
"We’re passively helping each other," Chen says.
- Rai, A.C. and Chen, Q. 2012. "Simulations of ozone distributions in an aircraft cabin using computational fluid dynamics," Atmospheric Environment, 54, 348-357.
- Wang, M., Lin, C.-H., and Chen, Q. 2012. "Advanced turbulence models for predicting particle transport in enclosed environment," Building and Environment, 47, 40-49.
- Liu, W. Mazumdar, S., Zhang, Z., Poussou, S.B., Liu, J., Lin, C.-H., Chen, Q. 2012. "State-of-the-art methods for studying air distributions in commercial airliner cabins," Building and Environment, 47, 5-12.