Modelling in applied hydraulics: More accurate in decision making than in science?

Marked differences occur between modelling in scientific hydraulic research, in hydraulic engineering and in public decision making. This study reviews ifferences in the required accuracy of model results and differences in the choice between physical and numerical modelling. Physical models are used for studying elementary processes and their...

Modelling in applied hydraulics: More accurate in decision making than in science? (PPT)

Marked differences occur between modelling in scientific hydraulic research, in hydraulic engineering and in public decision making. This study reviews ifferences in the required accuracy of model results and differences in the choice between physical and numerical modelling. Physical models are used for studying elementary processes and their...

Effects of strain rates on the undrained shear strength of kaolin

In recent times, interest in dynamically installed foundation systems for deep-sea construction has increased; however, these foundation systems are still under development and need quantification of various soil parameters with different perspectives. For the design of dynamically installed foundations, it is essential to assess the strain...

Efficacy of analysis techniques in assessing broken wave loading on a cylinder upon a shoal

Estimation of impulsive wave loading on a cylinder upon a shoal, such as an offshore rock lighthouse constructed on a partially emerged offshore rock with a steep foreshore, poses a unique challenge to marine structural engineers. Large and small scale experimental investigations are the most feasible methods to study this phenomena. However,...

Validation of pressure-impulse theory for standing wave impact loading on vertical hydraulic structures with short overhangs

The applicability of pressure-impulse theory is evaluated for predicting wave impact loading magnitudes for non-breaking standing wave impacts on vertical hydraulic structures with relatively short overhangs. To this end, tests were carried out on a schematized but realistic configuration with low steepness regular wave impacts on a straight...

Influence of toe berm geometry on stability of reshaping berm breakwaters

Reshaping berm breakwaters have been mainly designed and built for water depth less than 20 m. In such conditions, a toe structure may be needed to reduce bottom settlements and increase geotechnical stability in the loose subsoil condition. Also, a toe berm can be deployed to reduce the berm recession and increase the stability of the...

Numerical and physical modelling of the effect of groynes lowering

A Bayesian inverse dynamic approach for impulsive wave loading reconstruction: Theory, laboratory and field application

The measurement of wave forces acting on marine structures is a complicated task, both during physical experiments and, even more so, in the field. Force transducers adopted in laboratory experiments require a minimum level of structural movement, thus violating the main assumption of fully rigid structure and introducing a dynamic response...

Numerical and small-scale physical modelling of wave transmission by wooden fences

Mangrove forests, that often act as natural coastal defences, enormously suffered due to ongoing climate change and human disturbances. Thus, it is necessary to have a countermeasure to mitigate the loss of mangroves. Wooden fences are becoming a viable nature-based solution to protect vulnerable replanted mangrove forests. However, the wooden...

Large-scale physical modelling of static liquefaction in gentle submarine slopes

Planning a monitoring campaign for a natural submarine slope prone to static liquefaction is a challenging task due to the sudden nature of flow slides. Therefore, gaining a better insight by monitoring the changes in pore pressure and acceleration of the soil mass, prior to and at the onset of static liquefaction, of submerged model slopes...

Two-phase air-water flows in hydraulic jumps at low Froude number: Similarity, scale effects and the need for field observations

A hydraulic jump is a region of rapidly-varied flow that is extremely turbulent. While the one-dimensional continuity and momentum principles have been successfully applied to express the relationships between upstream and downstream conditions, the three-dimensional equations cannot be resolved without some complicated turbulence closure,...

Hydraulic jumps with low inflow Froude numbers: air–water surface patterns and transverse distributions of two-phase flow properties

Abstract: Hydraulic jumps are commonly employed as energy dissipators to guarantee long-term operation of hydraulic structures. A comprehensive and in-depth understanding of their main features is therefore fundamental. In this context, the current study focused on hydraulic jumps with low Froude numbers, i.e. Fr₁ = 2.1 and 2.4, at...

Effect of probe size on phase-detection probe measurements of air-water flow properties in hydraulic jumps

This experimental study investigated the air-water flow properties and bubble characteristics in hydraulic jumps with Froude numbers Fr₁ = 2.4 and 6.3, using four dual-tip phase detection probes with sensor sizes from 0.25 mm to 0.64 mm. The hydraulic jumps were characterized by a fully breaking roller with substantial air...