Untersuchungen zur Praxistauglichkeit von CFD-Berechnungen bei der Windlastermittlung auf Bauwerke durch Vergleich mit Windkanalversuchen

摘要

The wind load distribution on simpler structures is usually determined on the basis of the relevant standards, whereas wind tunnel tests are required for more complex structures. In addition, the wind load distribution can, in principle, also be determined by using CFD simulations. By simplifying the calculation model (RANS, SST) practical calculation times can be achieved, but as a consequence only time-averaged wind load coefficients can be calculated. In the wind tunnel test, however, wind load time series including short-term peak values are measured. There are now cases in which the engineer is not sufficiently supplied with the specifications of the wind load standard, but which do not yet justify a wind tunnel test The present investigations relate specifically to these cases. In a first step, the question arises whether the basic values, i.e. the time-averaged pressure and suction coefficients, can be determined with sufficient accuracy using CFD (RANS). For this purpose, the time-averaged coefficients in the wind tunnel as well as by CFD were determined and compared based on a sharp-edged building geometry. In summary, it can be concluded that the values match relatively well in terms of sign and tendency, but that in some cases deviations were found. Time-averaged coefficients, which were calculated with CFD (RANS), can be helpful for simpler geometries, which are not adequately recorded in the standard, for the development of wind load assumptions, but due to the existing investigations, they are mostly only suitable for pre-dimensioning.