260 The UMAP Journal 23.3 (2002) For concreteness, we focus on the plaza configuration of Figure 7. Most importantly, the fountain is at the center of a circular pool of radius 5 m 50m Figure 7. The layout of our hypothetical model plaza We display the spray distance as a function of wind speed and nozzle speed in Figure 8. An estimate of how far a water droplet can travel starting at height zo, falling at its terminal velocity vt, and moving at horizontal wind speed w is distance≈ The smallest droplets that our simulations produce have radii of about 1 mm with corresponding terminal velocity 7m/s. For specific heights and winds,we find that this rough estimate is usually within 30% of the corresponding min- imum safe distance shown in Figure 8, a good indication that our simulations produce reasonable results The Control algorithms We formulate four control algorithms Averaging Algorithm: This algorithm considers an average of the previous 10 min of wind data and the sample variance The worst-case scenario is estimated to be a wind strength of one standard deviation above the average260 The UMAP Journal 23.3 (2002) • For concreteness, we focus on the plaza configuration of Figure 7. Most importantly, the fountain is at the center of a circular pool of radius 5 m. Figure 7. The layout of our hypothetical model plaza. We display the spray distance as a function of wind speed and nozzle speed in Figure 8. An estimate of how far a water droplet can travel starting at height z0, falling at its terminal velocity vt, and moving at horizontal wind speed w is distance ≈ z0w vt . The smallest droplets that our simulations produce have radii of about 1 mm with corresponding terminal velocity 7 m/s. For specific heights and winds, we find that this rough estimate is usually within 30% of the corresponding min￾imum safe distance shown in Figure 8, a good indication that our simulations produce reasonable results. The Control Algorithms We formulate four control algorithms: • Averaging Algorithm: This algorithm considers an average of the previous 10 min of wind data and the sample variance. The worst-case scenario is estimated to be a wind strength of one standard deviation above the average