DECENTRALISED PI CONTROL OF AN OPEN WATER CHANNEL

This work analyzes the effects of the interaction between an oscillating sphere and free surface flows through the reconstruction of the flow field around the body and the analysis of the displacements. The experiments were performed in an open water channel, where the sphere had three different boundary conditions in respect to the flow, defined as h* (the ratio between the distance of the sphere upper surface from the free surface and the sphere diameter). A quasi-symmetric condition at h* = 2, with the sphere equally distant from the free surface and the channel bottom, and two conditions of asymmetric bounded flow, one with the sphere located at a distance of 0.003m from the bottom at h* = 3.97 and the other with the sphere close to the free surface at h* = 0, were considered. The sphere was free to move in two directions, streamwise (x) and transverse to the flow (y), and was characterized by values of mass ratio, m* = 1.34 (ratio between the system mass and the displaced fluid mass), and damping ratio, ζ = 0.004. The comparison between the results of the analyzed boundary conditions has shown the strong influence of the free surface on the evolution of the vortex structures downstream the obstacle.

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Offset-Free Model Predictive Control of an Open Water Channel Based on Moving Horizon Estimation

Journal of Irrigation and Drainage Engineering ◽

10.1061/(asce)ir.1943-4774.0001085 ◽

2017 ◽

Vol 143 (3) ◽

Cited By ~ 5

Author(s):

Boran Ekin Aydin ◽

P. J. van Overloop ◽

Martine Rutten ◽

Xin Tian

Keyword(s):

Model Predictive Control ◽

Predictive Control ◽

Water Channel ◽

Open Water ◽

Moving Horizon Estimation ◽

Free Model

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Modified Equation of Impulse for Solitons in an Open Water Channel

Theoretical Physics ◽

10.22606/tp.2021.61001 ◽

2021 ◽

Vol 6 (1) ◽

Author(s):

A. N. Volobuev ◽

Keyword(s):

Solitary Wave ◽

Continuity Equation ◽

Water Channel ◽

Open Water ◽

Geometrical Characteristics ◽

Correct Calculation ◽

The Given ◽

The Waves ◽

Modified Equation ◽

Impulse Equation

On the basis of the certain form of write of an impulse equation the modeling of the solitary waves in the water channel is examined at action of gravitation forces. It is shown that as against an existing method of modelling where the waves propagating from left to right turn out from the equation of an impulse, and from right to left from the continuity equation in the offered technique both waves turn out from the equation of impulse. It is marked that the given method is physically more correct. Calculation of a solitary wave, its velocity and geometrical characteristics is submitted.

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Wind–Water Experimental Analysis of Small SC-Darrieus Turbine: An Approach for Energy Production in Urban Systems

Sustainability ◽

10.3390/su13095256 ◽

2021 ◽

Vol 13 (9) ◽

pp. 5256

Author(s):

Eduardo Blanco-Marigorta ◽

Ahmed Gharib-Yosry ◽

Aitor Fernández-Jiménez ◽

Rodolfo Espina-Valdés ◽

Eduardo Álvarez-Álvarez

Keyword(s):

Wind Tunnel ◽

Urban Communities ◽

Smart Cities ◽

Water Channel ◽

Open Water ◽

Turbine Rotor ◽

Urban Systems ◽

Water Current ◽

Flume Tests ◽

Compact Size

Smart cities have a significant impact on the future of renewable energies as terms such as sustainability and energy saving steadily become more common. In this regard, both wind and hydrokinetic compact-size turbines can play important roles in urban communities by providing energy to nearby consumption points in an environmentally suitable manner. To evaluate the operation of a Darrieus turbine rotor as a wind or hydro microgenerator, a series of wind tunnel and water current flume tests were performed. Power and characteristic curves were obtained for all test conditions. In the wind tests, all curves seemed to be identical, which means that the turbine rotor works properly under open-field conditions. Two blockage correction equations were applied to the water channel tests that were performed under blockage values ranging from 0.2 to 0.35 to estimate the operational behavior in open water. Finally, it has been demonstrated that, with the condition of maintaining the Reynolds number between experiments in the wind tunnel and water flume, the turbine wind characteristics represents the its operation in open-water conditions.

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An Experimental Study of Surface-Mounted Bluff Bodies Immersed in Deep Turbulent Boundary Layers

Volume 1: Flow Manipulation and Active Control; Bio-Inspired Fluid Mechanics; Boundary Layer and High-Speed Flows; Fluids Engineering Education; Transport Phenomena in Energy Conversion and Mixing; Turbulent Flows; Vortex Dynamics; DNS/LES and Hybrid RANS/LES Methods; Fluid Structure Interaction; Fluid Dynamics of Wind Energy; Bubble, Droplet, and Aerosol Dynamics ◽

10.1115/fedsm2018-83498 ◽

2018 ◽

Author(s):

Helen A. Amorin ◽

Xingjun Fang ◽

Mark F. Tachie

Keyword(s):

Boundary Layer ◽

Experimental Study ◽

Aspect Ratio ◽

Water Channel ◽

Open Water ◽

Step Height ◽

Bluff Bodies ◽

Reynolds Stresses ◽

Reattachment Length ◽

Aspect Ratios

This paper reports an experimental study conducted to investigate the effects of aspect ratio on the reattachment length and statistical properties in turbulent flow over three-dimensional surface-mounted bluff bodies. This study focuses on a surface-mounted body whose height is significantly smaller than the thickness of the approaching turbulent boundary layer. The studied aspect ratios of the step range from w/h = 0.5 to 20, where w and h denote the spanwise width and height of the step, respectively. All experiments were carried out in an open water channel, and the velocity measurements were performed using a time-resolved particle image velocimetry (TR-PIV) system. The Reynolds number, based on the freestream of the approach boundary layer and step height, is 12540, while the ratio of the boundary layer to step height is 4.83. Two distinct regions of separation are observed on top of the step and downstream of the step. In both separation regions, the reattachment length increases monotonically as aspect ratio increases from w/h = 0.5 to 8, and the reattachment length reaches an asymptotic value and does not vary significantly with aspect ratio larger than 8. The effects of aspect ratios on the mean velocities and Reynolds stresses were also examined.

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