Abstract
Pressure fluctuations beneath hydraulic jumps potentially endanger the stability of stilling basins. This paper deals with the mathematical modeling of the results of laboratory-scale experiments to estimate the extreme pressures. Experiments were carried out on a smooth stilling basin underneath free hydraulic jumps downstream of an Ogee spillway. From the probability distribution of measured instantaneous pressures, pressures with different probabilities could be determined. It was verified that maximum pressure fluctuations, and the negative pressures, are located at the positions near the spillway toe. Also, minimum pressure fluctuations are located at the downstream of hydraulic jumps. It was possible to assess the cumulative curves of pressure data related to the characteristic points along the basin, and different Froude numbers. To benchmark the results, the dimensionless forms of statistical parameters include mean pressures (P*m), the standard deviations of pressure fluctuations (σ*X), pressures with different non-exceedance probabilities (P*k%), and the statistical coefficient of the probability distribution (Nk%) were assessed. It was found that an existing method can be used to interpret the present data, and pressure distribution in similar conditions, by using a new second-order fractional relationships for σ*X, and Nk%. The values of the Nk% coefficient indicated a single mean value for each probability.
Highlights
In hydraulic jumps, the high-velocity of an incoming flow abruptly has an impact against a slower flow [1]
The results showed that maximum pressure fluctuations were identified at the center of the vertical curve and assume values of 1% of the flow kinetic energy at the terminal tangency point of the curve
Where X is the longitudinal distance of each pressure tap from the spillway toe; Pm is the mean pressure at the point X; Nk% is the dimensionless statistical coefficient of the probability distribution at the point X; σX is the standard deviation of pressure fluctuations at the point X
Summary
The high-velocity of an incoming flow abruptly has an impact against a slower flow [1]. They proposed dimensionless relationships linking pressure data of P*k% to the mean pressure (P*m), and the standard deviation of the sample data (σ*X) Such relationships allow us to organize the results of different flow discharges or Froude numbers and characterize the interest points in hydraulic jumps. Many laboratory-scale experiments were designed to no indications are given to the different types of hydraulic jump, pressure regime, and simulate the flow patterns downstream forces on the bed of stilling basins [33].of an Ogee spillway, cascading into a USBR type I stilling. The focus of this study is the distribution mathematical analysis extreme pressures distribution the statistical of the probability (Nk% ) of tothe estimate the extreme pressures with at the bottom of a smooth stilling basin for different non-exceedance probabilities
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
