Computational wind–structure interaction simulations of high rise and slender structures and validation against on-site measurements — Methodology development and assessment

This contribution proposes a high-fidelity simulation approach for high-rise and slender structures in wind and a suitable validation strategy of the wind–structure interaction computations against on-site measurements instead of comparing to scaled wind-tunnel measurements. Concerning the level of abstraction and modeling in simulation, one usually distinguishes between low- and high-fidelity simulations. Thus, the term fidelity expresses the degree to which the details of the real-world scenario are represented in the numerical simulation model. As a consequence, a high-fidelity approach, as it is elaborated in this contribution, can provide very detailed insights. Whereas the developed procedures are rather general, all steps are demonstrated at the example of the Olympic Tower in Munich, in order to prove their applicability for complex real-world problems and especially to highlight the respective challenges and relevance of certain aspects in modeling, simulation and validation. This holistic simulation and validation approach contains many linked aspects and it is thus presented stepwise as follows. In a first step, the numerical methodology is shortly presented, which inherits the finite element formulations for modeling the fluid flow and the structure in up to a very high level of fidelity. Additionally, the coupling methodology and the mapping operation for the partitioned wind–structure coupling approach is introduced. In a second step, the main characteristics of the structural system of the Olympic Tower in Munich and the measured turbulent wind field are presented. Within the numerical simulation, the respective wind field is realized via a synthetic inlet generator. This wind field was validated against the wind characteristics available from the on-site measurements before being further applied to the coupled wind–structure interaction simulations. Furthermore, convergence studies and validation simulations for the single subproblems, i.e. fluid flow and structural dynamics, are presented. In a third step, the results of the wind–structure interaction simulations, which are conducted in real scale, are presented. Those contain, besides some convergence studies and validation of the fluid flow results, the comparison of the tower's reaction moments in the lateral and longitudinal direction to the on-site measurements. This comparison shows good accordance between simulated and on-site measured values while identifying possible deficiencies in the measurement methodology, thus demonstrating the potentials of Computational Wind Engineering approaches for assessment of wind-induced transient effects of slender high-rise structures in complex atmospheric-boundary-layer flows.