The opera ‘Carmen’ is one of the world’s most famous and successful productions. In November 2012, it was performed at TU Delft by talented young international artists. The performance was fresh, innovative, unconventional, and challenging. The centrepiece of the production was a portable flagpole featuring a flag that could be hoisted to flutter in the wind, despite it being an indoor event.
FlowMotion was commissioned to develop, build, and install this flagpole. However, fulfilling this challenge required an extensive research and development programme. Initially, FlowMotion defined and examined all unknown aspects and constraints at the project’s outset, including the required wind speed, wind generation, flag material, mast construction, handling of the mast, and the substructure within the raised floor beneath the stage.
The most important and difficult design goal for the indoor flag was the director’s requirement that the noise level of the entire construction, the airflow through the flagpole, and the air jets be kept to a minimum. Initial studies took place in the TU Delft wind tunnel to understand the relevant flow effects of a flag moving in the wind. The wind tunnel tests examined various wind speeds and flag materials. Subsequently, the airflow through the pumps, the flagpole, and the nozzles—which keep the flag in motion—were investigated and determined in FlowMotion’s laboratory.
To ensure the flag fluttered in a natural, credible, and almost silent manner at very low wind speeds, high-quality, ultra-lightweight pure silk was selected after numerous tests. This had to be produced using a special sewing technique involving three fabric panels, making the flag a work of art in its own right. During initial rehearsals, the entire system—pump, air lines, flagpole, and flag—was tested with great success. Noise disturbance was virtually undetectable, and the effect of the fluttering flag on the stage was exactly as the director had envisioned: ‘Fire and Passion’.
Through this project, FlowMotion not only demonstrated its excellent consultancy services but also its ability to develop and manufacture products. The indoor flagpole will be used in the future not only in theatres but also at trade fairs.
