Hydraulic jump on smooth and uneven bottom

The mechanism of absorption of excess power of the flow within hydraulic jump has been studied in the article based on theoretical manner. Mathematic model of hydraulic jump has been investigated by taking additional water body (mass) in hydraulic jump zone as basic. Theoretical research has shown that main part of excess power is discharge for rotation of additional water mass and a formula has been obtained to make calculation thereof. The article also has provided a formula for calculating the portion of flow energy needed for overcoming friction resistance emerged in bed bottom. Because of conducted studies, formulas have been suggested for calculating hydraulic jump length occurred in flat and uneven beds. Obtained formulas have been mutually analyzed with results found by other researchers.