Jens Fransson

Jens H. M. Fransson has a master's degree in engineering physics (sv. teknisk fysik) from KTH – Royal Institute of Technology from 1999. He received his Ph.D. in 2004 in fluid mechanics and became an associate professor (sv. docent) in fluid physics in 2007 at the same university, KTH. In 2009 he obtained a lectureship at the Department of Mechanics, KTH, and was promoted to professor in experimental fluid mechanics in 2013. Since January 2013, he also holds a part-time professorship in indoor environment at the University of Gävle.

Jens has been awarded the Göran Gustafsson prize for outstanding young researchers twice, in 2005 and 2008. In 2010, he received a prestigious ERC (European Research Council) grant for young researchers for his project AFRODITE. His basic research in experimental flow control has attracted much international attention over the years. Today, Jens is also active in a number of more applied research projects in the automotive and wind energy aerodynamics.

 

Popular science subject description

The air flow around a vehicle, the movement of paper pulp through the roller in a paper mill, the flow of blood through an artery, the wind in a wind turbine and the water flowing around a professional swimmer are all examples of fluid physics phenomena. Each of these cases involves the flow of a fluid. The ability to control the flow and regulate whether it is laminar (well ordered) or turbulent (chaotic) is central to many of these examples.

Jens Fransson’s research mainly involves developing these control methods and gaining a better understanding of how laminar flow becomes turbulent flow. A few years ago, his group presented wind tunnel data, which directly contradicted the conventional view that surface roughness results in turbulent flow. Their research showed that placing small, well designed “pucks” in the right place on a surface can hold back the conversion to turbulence, resulting in reduced resistance for example.

The results show that if the flow can be controlled so that it does not become turbulent, operating costs can be reduced in a number of areas within fields such as the automotive and process industries, where fluid mechanics plays a central role. Even more importantly, reduced resistance could also protect the environment from unnecessary emissions, which can have a global climatic impact.