The quantification of water depths resulting from rain events on highways is presented using concepts of flows along flat plates. The hydrodynamics of the water film was developed by taking the basis of the fluid–surfaces interaction, generating equations for the depth of the films that reproduce adequately measured data considering the equilibrium between impulsive and resistive forces. To consider geometrical changes, corrective parcels were added, obtained through dimensional analysis involving the depth of the texture of the pavement. The exponents and coefficients of the formulation were adjusted to better reproduce literature data and check the adequacy of the obtained solutions. The hydroplaning phenomenon was treated using the integral formulation of the principles of conservation of mass and momentum, inserting information of the tread grooves in the control volume equations, which evidences its effect on the general hydroplaning velocity. Both the formulations (film thickness and hydroplaning) are presented in nondimensional form to allow their use with any system of units. The good correlations obtained between measurements and predictions show that the hydrodynamics of both the water films and the hydroplaning phenomenon were adequately quantified through the application of the basic physical principles. The resulting equations can help design purposes and be used in further studies on this theme.

The Darcy–Weisbach equation was used in the analysis of flow over spillways, furnishing theoretical tools to design stilling basins. Predictions for the length of hydraulic jump stilling basins downstream of stepped and smooth spillways are presented, together with ranges of values for the Darcy–Weisbach friction factor of both spillways. The experimental data were compared with results of the theoretical solution of the gradually varied flow equation. All comparisons were made in non-dimensional form. The values of the Darcy–Weisbach friction factor were roughly five times smaller for smooth spillways than for stepped spillways. The theoretical predictions and the experimental data allow to present approximate equations for a preliminary evaluation of the length and the bed level of hydraulic jump stilling basins. In the same way, approximate equations were presented for the evaluation of the friction factor in smooth and stepped spillways, as a function of the Froude number at the downstream cross-section.

Details of Hydraulic Jumps for Design Criteria of Hydraulic Structures | InTechOpen, Published on: 2015-04-01. Authors: Harry Edmar Schulz, Juliana Dorn Nóbrega, André Luiz Andrade Simões, et

The impacts caused by flood waves due to dam ruptures usually cause irreversible damages to the resident population, and, the loss of body equilibrium in floods contributes to aggravate this scenario. In this context, this work aimed to analyse the influence of consideration of physical mechanisms that cause instability in the human body on the definition of hazard zones. Therefore, it was developed simulation of the propagation of the flood wave due to the hypothetical rupture of Santa Helena Dam in Bahia, using the hydrodynamic model HEC-RAS. The results of flow velocities and heights were related and compared to different criteria of hazard zonings and mechanisms that cause body instability. It was verified that the consideration of instability mechanisms of the human body can contribute to hazard management, through the knowledge of areas in which different individuals may topple or slide. It was confirmed that in supercritical flow regimes is more likely for the individual to slide and that in subcritical regimes the individual will topple. Moreover, the consideration of parameters such as buoyancy force and the angle related to the human body's adaptive ability in a flooding influence on the definition of zones.