The flow field downstream of a hydraulic jump
نویسنده
چکیده
A control-volume analysis of a hydraulic jump is used to obtain the mean vorticity downstream of the jump as a function of the Froude number. To do this it is necessary to include the conservation of angular momentum. The mean vorticity increases from zero as the cube of Froude number minus one, and, in dimensionless form, approaches a constant at large Froude number. Digital particle imaging velocimetry was applied to travelling hydraulic jumps giving centre-plane velocity field images at a frequency of 15 Hz over a Froude number range of 2-6. The mean vorticity determined from these images confirms the control-volume prediction to within the accuracy of the experiment. The flow field measurements show that a strong shear layer is formed at the toe of the wave, and extends almost horizontally downstream, separating from the free surface at the toe. Various vorticity generation mechanisms are discussed.
منابع مشابه
Characteristics of S-jump on Roughened Bed Stilling Basin
Formation of hydraulic jump is necessary for dissipation of the excess kinetic energy downstream of spillways and gates. Hydraulic jump stilling basins of sudden expansion are one of the energy dissipater structures which are used where the available tail water depth is less than the required sequent depths. In the present study to further reduce the hydraulic jump sequent depths ratio, a rough...
متن کاملبررسی آزمایشگاهی اثر تخلیه تحتانی سد انحرافی روی مشخصات پرش هیدرولیکی
One of the usual ways to dissipate excess energy in the dam's downstream is hydraulic jump. Hydraulic jump is a rapidly varied flow, in which the flow conditions change from supercritical to sub-critical with a large amount of energy loss. In this research, a combination of two water jets in the form of overflow dam and underflow through a slot on the body of an ogee dam with the USBR standard ...
متن کاملThe Effect of Six-Legged Concrete Elements on Hydraulic Jump Characteristics
In the present study, the six legged concrete (SLC) elements are placed at the bed of a flume downstream of a chute in different layouts, densities and number of longitudinal rows of SLC elements. Each test was run for different flow conditions (Froude numbers ranged 5.3 to 8.1). During each test, the water surface profile, the roller length and the jump length measured. Applying the experimen...
متن کاملExperimental Investigation of the Characteristics of Hydraulic Jump in a Diverging Stilling Basin with an Adverse Slope Using Baffle Blocks
Stilling basins have been used as an energy dissipater downstream of hydraulic structures. Dimensions of the stilling basins depends on hydraulic jump characteristics. In this research diverging hydraulic jump with an adverse slope using baffle blocks and an end sill have been studied experimentally and effect of diverging angle of the walls, adverse bed slope and baffle blocks on the hydraulic...
متن کاملExperimental Study of the Effect of Gabion Structure on the Energy Dissipation of Submerged Hydraulic Jump Downstream of Ogee Spillway
In the last decade, the use of gabion structures in hydraulic engineering for stabilizing the structure due to its high density and weight has become widespread. Also, the material's roughness and porosity cause it to be used in energy dissipation and drainage projects. This study evaluates the relative energy dissipation of gabion structures downstream of the ogee spillway in the conditions of...
متن کاملEffect of dredging on hydraulic and reduce flood in downstream river (Case study: Karun River downstream interval between Ahvaz and Farsyat)
This study modeled the effects of hydraulic dredging on the lower Karun river in Ahvaz range to thevillage is Farsyan . using software 4.1 HEC-RAS, one-dimensional model of the flow field wassimulated . After entering the information into the model and its calibration based on the selected,design flow model was implemented to extract the water surface elevation levels and spreading areaswere me...
متن کامل