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GPD Finland 2011: CFD Modeling with Daniel Bettenhausen

Thursday, April 28, 2011

While still a relative newcomer to the Enclos team, Mechanical Engineer Daniel Bettenhausen inherited a rather full plate in 2009. The Lakeville, Minnesota native has played a crucial role in over a dozen university, healthcare and civic projects while at Enclos, including many high-profile jobs such as the Javits Convention Center and Columbia University Manhattanville Campus. At GPD Finland 2011, Bettenhausen — also a Ph.D. Candidate at the University of Minnesota — will publish and speak about the Computational Fluid Dynamics (CFD) research and analysis he’s applying to his work at Enclos.

How’d you get started as an engineer?

Daniel Bettenhausen: I had an affinity for industrial technology in high school. If you had asked me prior to then I would have said that I expected to work as a mechanic or machinist. I had reservations about some college programs, and the first couple of years took some adjustment, but as the focus shifted from fundamentals to applications I was able to find motivation in the work I was doing.  I had the good fortune of crossing paths with a like-minded faculty professor, and now look back at the years I spent in the graduate program at the University of Minnesota as being one of the more enjoyable periods of my life.

How’d you end up at Enclos?

My focus in graduate school was thermal science, and the prospect of dealing with the thermal aspects of facade design seemed like a natural fit.

Why focus exclusively on building skins?

The building facade is unique from a thermal perspective in that it encompasses such a broad array of physics. Forced and natural convection, conduction, radiation and psychometrics (the study of humid air and condensation) are all significant.

What makes your CFD research conducted at Enclos timely in 2011?

The building facade could be said to be in a state of design evolution, where so called “breathing skins”, i.e. double skin facade systems, active glazing and the use of phase change materials are becoming more prevalent.  Regulation and energy code enforcement will inspire the development of such technologies by adapting to accommodate and reward these technologies.

Below is an excerpt from Bettenhausen’s "CFD Modeling of Wind-Driven Convection Heat Transfer in Framed Cavities of Glazed Wall Systems" paper selected by the conference.

“Modeling by the methods of numerical analysis that are employed in the planning stages of construction aimed at reducing the energy consumption of commercial buildings have been a strong focus of building science research in recent decades due primarily to rising energy costs and environmental concerns.  An example of one such method routinely encountered in industrial practice is the use of Finite Element Analysis (FEA) to assess the thermal transmittance of fenestration products by solution of a heat-conduction based model.  Heat conduction based models rely on correlations to approximate the effects of natural convection and radiation in closed frame cavities by an adjusted thermal conductivity of air.  This approach is challenged when wind driven airflow permeates glazed wall systems and enters frame cavities through orifices introduced by gaskets, rain screen openings and other features. This study explores the dependence of heat transfer coefficients throughout surfaces of a glazed wall system interior to the primary wind impingement surface as a result of such aforementioned orifices by the method of computational fluid dynamics (CFD) and compares those results to values predicted by a correlation based approach.”

Bettenhausen will lecture on "CFD Modeling of Wind-Driven Convection Heat Transfer in Framed Cavities of Glazed Wall Systems" as part of the Energy Performance in Buildings program on Saturday, June 18. We hope you’ll join us in Finland.