Wind on the Euro50 enclosure

The Euro50 is a European Extremely Large Telescope. Its enclosure will be among the largest buildings of the world. Determining the maximum wind load is crucial for the survival of the structure, and local forces have an impact on the detailed design such as cladding. Pressure variations on the primary mirror and the wind load on the telescope are important for the development of active optics and segment control systems. To obtain data for the survival wind load as well as for typical observing conditions, the airflow pattern has been studied both with a wind tunnel model and computational fluid dynamics (CFD). Special attention has been given to determination of pressures on the primary mirror. Results are compared for the two methods and also with data available from previous studies and from measurements on existing telescopes. Finally, a typical wind load envelope is defined for the integrated telescope model.