Characterization of Hydraulic Power in Free-Stream Installations

Figure 6

Power curves for an ideal actuator surface machine, for different values of the drop coefficient . The case corresponds to the well-known solution for an actuator surface without any loss, now associated with Betz and Joukowski. Positive values of correspond to increased pressure drop across the device; increasingly negative values of may occur due to increasing pressure losses. Note that negative values (or , above the straight horizontal line in this figure) correspond to hydraulic power being extracted by the device, which is obviously the objective.