The work is devoted to the rectangular sharp-crested weir calculation methods improvement. This can be realized by using mathematical model developed on energy and momentum conservation principles. In order to get energy conservation equation within sharp-crested weir we have to know weir head losses. This article presents theoretical and experimental investigations of the sharp-crested weir head losses. The height of the weir plate pw and weir head H are estimated as main operating factors that determine hydraulic weir outbound parameters: threshold depth h and the specific weir flow q. The flow moving over sharp-crested weir suffers sudden vertical contraction and transforms from the uniform flow to a jet. Mentioned above, causes sharp-crested weir head losses. To determine these losses, we propose to use Hind’s formula that describes similar contraction losses in the channel. Experimental investigations proved Hind’s formula application adequacy to evaluate these losses. Sharpcrested weir energy conservation equation that includes head losses is determined. Graphs set out in the article disclose the influence of the main operating factors and their ratio on the relative head losses.
W artykule omówiono podstawowe zagadnienia związane z potrzebą wzrostu pozyskiwania energii elektrycznej, tzw. energii odnawialnej, z źródeł niekonwencjonalnych, co jest jednym z postulatów stawianych przed krajami członkowskimi Unii Europejskiej. Omówiono takie źródła energii elektrycznej, jak: energia geotermiczna, energia wiatrowa, energia pływowa (tj. energia przypływów i odpływów wód w morzach i oceanach) oraz energia wytwarzana w czasie spalania drewna wierzby energetycznej.
EN
The article describes the fundamental problems concerning to the need of grow of the obtaining of the electrical energy, so-called renewable energy, from unconventional sources, what is one from demands, which the European Union sets before membership countries. The article discusses such sources of electrical energy as: geothermic energy, wind energy, flow energy (that is energy from high tide and from low tide in seas and oceans) and from the energy produced during combustion of the energy-willow-wood.
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