Stability analysis of non-linear sampled data systems with time varying sample period and delay in the feedback loop

In almost all practical applications of control, technological and economical consid -erations impose limits on communication speed, frequency of communication, and frequency of actuator adjustment. Such limits turned the analysis of sampled data systems into a flourishing field. Water systems pose a particular challenge: the systems are...

Drivers for mass and momentum exchange between the main channel and river bank lateral cavities

Large-Eddy Simulations (LES) are used to investigate the governing processes involved in mass and momentum transfer between the flow in the main channel and symmetrically-distributed lateral bank cavities. In-cavity free-surface velocities, based on laboratory measurements made in an open channel, are used to validate the numerical results. A...

Development of in/outflow boundary conditions for MPM simulation of uniform and non-uniform open channel flows

This paper describes the development and application of inflow and outflow boundary conditions (BCs) for the material point method (MPM) in order to simulate fluid flow problems. This corresponds to velocity and pressure controlled BCs. Due to the coupled Lagrangian and Eulerian description of the fluid motion in MPM it is necessary to add and...

Real-time Control of Combined Water Quantity & Quality in Open Channels

Fresh water supply and flood protection are two central issues in water management. Society needs more and more fresh water and a safe water system to guarantee a better life. A more severe climate will result in more droughts and extreme storms. As a consequence, salt water intrusion will increase. Therefore, clean and fresh water is becoming...

Flow and bathymetry in sharp open-channel bends: Experiments and predictions

This paper focuses on experiments and simulations conducted in very sharp open-channel bends with flat and equilibrium bathymetry, corresponding to the initial and final phases of the erosion and deposition processes, respectively. The study of flow in curved open bends is relevant for flow in natural river configurations, as most river reaches...

Design of open-channels and hydraulic structures

Lecture note on open channel hydraulics, hydraulic structures, regulators, weirs, drop structures and stilling basins.

Estimates of Roughness Coefficients for Selected Natural Stream Channels with Vegetated Banks in New York

Water-surface profiles were recorded and Manning's roughness coefficients computed for a range of discharges at 21 sites on unregulated streams in New York State, excluding Long Island. All sites are at or near U.S. Geological Survey streamflowgaging stations at which stage-to-discharge relations are relatively stable and overbank flow is absent...

Some aspects of the design and operation of water management systems

This study deals with the design of water management systems. Attention is focused on that phase in the design process in which variants are developed and evaluated with emphasis on the evaluation. The proposed evaluation procedure combines an economic evaluation with an evaluation of the hydraulic qualities- The economic evaluation implicates...

Waterverlies in waterlopen met een sterk doorlatende bodem

waterverlies in waterlopen treedt vooral op in gebieden waar het water stroomt over een sterk doorlatende bodem met een lage grondwaterstand. Over de wijze waarop de afstroming door de bodem plaatsvindt, en de invloed daarvan op het verloop van de waterdiepte, is nog weinig bekend. Door Schropp (1987) is een differentiaalvergelijking opgesteld...

Dynamic forces on a bed element in open channel flow with a backward facing step

Experiments to measure forces on objects in open channel flow behind a bacward facing step

Turbulence measurements using a small electromagnetic current meter in open channel flows

The use of a small two-component electromagnetic current meter to record turbulent velocities in a laboratory flume is described. The results from these experiments are compared with results obtained previously using different measuring techniques.

Turbulent structure in open-channel flows

Ph.D. thesis

Manuscripten van H.J. Schoemaker uit de periode 1946-1971: Deel B: Stroming in buisleidingen en kanalen

B1: Grondvergelijkingen van de hydrodynamica (1957) B2: Met de tijd veranderlijke stromen (1958) B3: Waterslag¹ (1959) B4: Waterslag, samendrukbare vloeistof in slappe buis met variërende doorsnede (1958) B5: Geleidelijk veranderde beweging in kanalen volgens Boussinesq (1968) B6: Geleidelijk veranderlijke beweging met zijdelingse aan- en afvoer...