Neues vom JSPS Club 05+06/2003

In den Jahren 2000 und 2001 erhielt Prof. Dr. K. G. Roesner für die Zusammenarbeit mit japanischen Kollegen vom Institute of Computational Fluid Dynamics in Tokyo Zuschüsse aus dem HWADJ-Fond. Auf diese Projekte sich anschließende Forschungsergebnisse werden in folgendem Beitrag vorgestellt.

Numerical simulation and experimental verification of a facade model for the natural ventilation of rooms

K. G. Roesner
Institut für Strömungslehre und Aerodynamik
Technische Universität Darmstadt

Fig.1: Sketch of the facade model (drawing by Stefan Menzel)

Fig.2: Streamlines near the outlet at the top of the double facade (picture taken by Stefan Menzel)

Fig.3: Result of the data analysis by Uemura’s software (picture taken by Stefan Menzel,

In cooperation with the Department of Civil Engineering (Prof. Stefan Schäfer and the Department of Mechanical Engineering (Prof. K. G. Roesner) of the Darmstadt University of Technology a project was started with the aim to get reliable information about the fluid dynamical characteristics of the flow in the model of a new type of facade. This double facade window type is designed to replace artificial air conditioning systems by natural ventilation on the basis of convective air flow. The ultimate goal of the investigation is the optimization of the parameters of the whole system. A sketch of the facade model is given in Fig.1.

The solution of problem was sought in two ways: In a first step numerical calculations on the basis of the direct numerical simulation were performed using the software package NAGARE which was developed by Prof. Kunio Kuwahara of the ICFD (Institute of Computational Fluid Dynamics, Tokyo), perfectly designed for the solution of the Navier- Stokes equations and the energy equation which plays a major role in the numerical approach. A picture of the streamlines near the outlet of the facade is described in Fig.2.

The implementation of the software on a workstation at the institute of Prof. Schäfer was done by Prof. Satoko Komurasaki of the Nihon-University, Tokyo, College of Science and Technology, who stayed in Darmstadt two times for a longer period of time, for which the financial support was partly contributed by the HWADJ-fond.

In a second step measurements were performed with the perspex model by Dipl.-Ing. Stefan Menzel in collaboration with Prof. K. G. Roesner using the Particle Image Velocimetry (PIV-method) for which the analysis of the pictures – taken by a laser sheet technique – was developed by Prof. Dr. Tomomasa Uemura of the Kansai University, Department of Industrial Engineering in Osaka. The collaboration of Prof. Uemura with Prof. Roesner dates back to the late nineties, when Prof. Uemura was invited to present his excellent method of Particle Image Velocimetry at the Darmstadt University of Technology. A typical picture of the results – taken at the entrance of the double facade window – is shown in Fig.3.