Hu and his team have studied the hydrodynamics of mammal urination. 

David Hu, an assistant professor in the Woodruff School of Mechanical Engineering, has been awarded the Ig Nobel Prize for his research on the hydrodynamics of mammal urination. The award was given by Improbable Research, which celebrates research that "makes people laugh and then think." The idea is to challenge what is considered important scientific research and illustrate that valuable information can come from more trivial subject matters. Every year there are 9,000 nominations, and only 10 teams are selected as winners. 

Hu was assisted by Patricia Yang, a mechanical engineering graduate student, and biomedical engineering undergraduates Jerome Choo and Jonathan Pham.

His research was directed by his interest in the link between the gravitational pull during urination and the advancement of efficient water systems. With camera in hand, Hu and his students ventured out to Zoo Atlanta to record and study 32 different mammals including elephants, cows and rats. By examining the video of the urine streams in slow motion, they were able to determine a relation between the length of the urethra and the flow rate of the urine. Their conclusion was that all mammals empty their bladders in about 20 seconds. 

Hu and his students were awarded the prize at the 25th annual Ig Nobel Prize ceremony on Sept. 17.