These tubes speed up the water flow, which makes for a greater power output than a similar sized turbine without a shroud. As seen in Figure 2, a funnel shape is built around or near the turbine that causes the flow rate of the water to increase. In the case of tidal stream generators, a duct or shroud (otherwise known as a diffuser) can be used to increase the amount of power available. The energy in this increased speed comes by reducing the static pressure of the fluid. The Venturi effect describes how the velocity of a fluid increases as the cross section of the container it flows in decreases (like when flowing through a funnel). The pressure at point 1 is higher than at point 2 however, due to the conservation of energy. The fluid flows faster in at point 2 than at point 1 due to the decrease in cross-sectional area. A diagram demonstrating the Venturi effect.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |