Wave flume tests of a semi-submersible platform controlled by a novel rotational inertia damper

2021 ◽  
Vol 238 ◽  
pp. 109718
Author(s):  
Ruisheng Ma ◽  
Kaiming Bi ◽  
Hong Hao
Keyword(s):  
Rotational Inertia ◽  
Wave Flume ◽  
Flume Tests

Experimental Wave Flume Tests in ROV-Wave Interaction Effects on the Line Tension for a Work Class ROV in Splash Zone

2021 ◽  
Author(s):  
Michael Binsar Lubis ◽  
Mehrdad Kimiaei
Keyword(s):  
Time History ◽  
Wave Interaction ◽  
Line Tension ◽  
Irregular Waves ◽  
Splash Zone ◽  
Remotely Operated Vehicle ◽  
Wave Flume ◽  
Flume Tests ◽  
Tension Time ◽  
Work Class

Abstract Integrity and stability of Remotely Operated Vehicle (ROV) when passing through the splash zone is one of the main concerns in the design of an ROV-umbilical system. Due to the lightweight nature of ROV in water, the umbilical experiences repetitive rapid transitions between slack and taut as the ROV travels through the splash zone. These rapid transitions induce tension spikes in the umbilical, namely snap forces, that can endanger the launch and recovery of an ROV. Therefore, it is important to ensure that the tension spikes do not exceed the safe working load of the umbilical. In this study, launch and recovery of a deep-water work class ROV are experimentally investigated using a 1:10 scaled ROV model through a series of wave flume tests. Different regular and irregular waves are generated in the flume while the ROV model is hung over the flume in four different positions. The tension time-history in the line is measured and recorded using a load cell at the top-end of the line. A simplified numerical model for launch and recovery of the ROV is developed and the numerical results are compared with the experimental ones. It is shown that the presented simplified model can be accurately used for analysis of launch and recovery of the ROV.

scholarly journals MAGNITUDE OF THE B-FACTOR UNDER WAVE ACTION

1986 ◽  
Vol 1 (20) ◽  
pp. 67
Author(s):  
J. Van de Graaff ◽  
R.C. Steijn
Keyword(s):  
Velocity Distribution ◽  
Water Depth ◽  
Sediment Concentration ◽  
Wave Action ◽  
Practical Applications ◽  
Wave Flume ◽  
Sediment Size ◽  
Flume Tests ◽  
Waves And Currents ◽  
The Moment

The sediment transport due to waves and currents depends on the distribution of sediment concentration and on the distribution of the velocity over the water depth. Our knowledge of both phenomena for practical applications is still rather poor. Some results of wave flume tests concerning the distribution of sediment concentrations due to wave action will be discussed. It turns out that the sediment size of the bottom material has a rather unexpected effect hereupon. With respect to the velocity distribution only some qualitative remarks can be made at the moment.

scholarly journals DESIGN OPTIMIZATION FOR A PASSIVE MESH SCREEN WAVE ABSORBER FOR THE CCOB

2012 ◽  
Vol 1 (33) ◽  
pp. 36
Author(s):  
Christian Klinghammer ◽  
Pedro Lomonaco Tonda ◽  
Pablo Higuera Caubilla
Keyword(s):  
Design Optimization ◽  
Physical Model ◽  
Ocean Basin ◽  
Back Wall ◽  
Wave Flume ◽  
Flume Tests ◽  
Mesh Screen ◽  
Wave Basin ◽  
Final Design ◽  
And Performance

A new passive wave absorber, consisting of multiple mesh screens, for the Cantabria Coastal and Ocean Basin (CCOB) was optimized regarding its overall length and performance. Physical model wave flume tests were conducted to calibrate and verify a 2D-RANS model utilizing different combinations of vertical and horizontal mesh screens. The final design of the main wave absorber at the back wall of the new CCOB was obtained by simulating different mesh screen configurations at full scale using the IH-2VOF model. Very good wave absorption over the entire working range of the wave basin could be achieved with a relatively short passive mesh screen wave absorber.

Probabilistic Modeling of Horizontal Wave-in-Deck Loads on a Square Concrete Deck

2020 ◽  
Vol 142 (5) ◽  
Author(s):  
Zhonghui Shen ◽  
Kai Wei ◽  
Peng Deng ◽  
Xi Zhong ◽  
Shunquan Qin
Keyword(s):  
Rise Time ◽  
Probability Model ◽  
Joint Probability ◽  
Offshore Structure ◽  
Wave Flume ◽  
Inundation Depth ◽  
Flume Tests ◽  
Horizontal Wave ◽  
The Impact ◽  
Concrete Deck

Abstract The square concrete deck is being used as an elevated transition piece in offshore structure but has a large exposure area to extreme waves. This study focused on the horizontal wave-in-deck loads on the square concrete deck. Wave flume tests were carried out to investigate the wave-in-deck loads on a specimen of a square concrete deck. Horizontal wave-in-deck loads on the specimen with ten different structural orientations were measured under three nonlinear regular wave trains. A novel analytical model of the horizontal wave-in-deck loads on the square thick deck was proposed by including both impact maxima and pulse shape function. The temporal development of the resultant horizontal wave-in-deck loads was studied from the measured forces through data post-processing. The effects of structural orientation, inundation depth, and the correlation between the rise and decay time were considered based on the experimental data. The marginal distributions of the impact maxima and rise time for the horizontal wave-in-deck loads on the square deck were investigated, and the joint probability model of impact maxima and rise time was finally developed using Plackett copula. The research provides a useful stochastic model in assessing the wave-in-deck loads on the square concrete deck.

scholarly journals ON DESIGN OF WAVM PRESSURE ACTING ON STRUCTURES OF SLOPING TYPE

1966 ◽  
Vol 1 (10) ◽  
pp. 53
Author(s):  
Krylov V.V ◽  
Selivanov L.V. ◽  
Nikerov P.S.
Keyword(s):  
Distribution Curve ◽  
Water Pressure ◽  
Wind Waves ◽  
External Pressure ◽  
Pressure Data ◽  
Wave Flume ◽  
Flume Tests ◽  
Test Zone ◽  
Maximum Water

In the paper some results of study of active external pressure of wind waves acting on structures of sloping type are presented in brief. The pressure developed by waves and acting on the inclined wall is divided into impact pressure and pressure remaining after shock. For determination of maximum water pressure remaining after shock a prof. N.N.Djunkovsky scheme is used (R.-I). Pressure distribution curve of water remaining after shock along the slope is determined by means of consideration of jet pressure acting on inclined wall. Design ourve is compared with the data of laboratory wave flume tests. Measurement pressure data received at test zone in reservoir is statistically treated.

Large wave flume tests on wave-induced response of sandy seabed adjacent a water intake

2020 ◽  
Vol 195 ◽  
pp. 106709 ◽  
Author(s):  
Xiaowen Wang ◽  
Songgui Chen ◽  
Rui Wang ◽  
Jian-Min Zhang
Keyword(s):  
Water Intake ◽  
Induced Response ◽  
Large Wave ◽  
Wave Flume ◽  
Flume Tests ◽  
Wave Induced

Wave-flume tests of a model-scaled OWC chamber-turbine system under irregular wave conditions

2020 ◽  
Vol 99 ◽  
pp. 102141
Author(s):  
Zhen Liu ◽  
Chuanli Xu ◽  
Hongda Shi ◽  
Na Qu
Keyword(s):  
Irregular Wave ◽  
Wave Flume ◽  
Flume Tests ◽  
Wave Conditions

Mean Flux in the Tree Surface Zone of Water Waves in a Closed Wave Flume

1995 ◽  
Author(s):  
Witold Cieślikiewicz ◽  
Ove T. Gudmestad
Keyword(s):  
Water Waves ◽  
Surface Zone ◽  
Wave Flume

APPLICATION OF ACOUSTIC METHODS IN RESEARCHES OF THE BOTTOM SEDIMENT DYNAMICS

2018 ◽  
Author(s):  
Б. Дивинский ◽  
B. Divinskiy ◽  
И. Грюне ◽  
I. Gryune ◽  
Р. Косьян ◽  
...  
Keyword(s):  
Suspended Sediment ◽  
Sediment Concentration ◽  
Irregular Waves ◽  
Single Frequency ◽  
Contactless Measurement ◽  
Measurement Means ◽  
Uniform Field ◽  
Wave Flume ◽  
Acoustic Methods ◽  
Back Scattering

Acoustic methods belong to contactless measurement means, possess high spatial and time resolution. Thus, the use of multifrequency allows directly profile both concentration and granulometric structure of the suspended substances. In 2008 in the Big Wave Flume (Hanover, Germany) by efforts of the Russian and German scientists there have been carried out the experiment on studying the bottom material suspension laws under the influence of irregular waves. The Aquascat 1000 acoustic back scattering sensor (ABS) manufactured by British company Aquatec (www.aquatecsubsea.com), equipped by a three-frequency transmitter with frequencies 1,0, 2,0 and 3,84 MHz, has been set on distance of 0,75 m from the bottom and 111 m from wave generator at the total depth of 3,2 m. Several dozen series of measurements at various parameters of surface waves have been carried out. The general picture of suspension is so that the external dynamic influence (currents, wave movements, turbulence, gravitation forces) creates a non-uniform field (gradient) of the suspended particles and in most cases due to this the average size of particles undergoes to the spatial-time variations. For this reason while defining the mass concentration of suspended sediment, using the single frequency transmitter there is necessity for numerous definition of the suspension granulometric structure what by isn’t always possible. If two and more frequencies are used the observed results comparison can give the information on average diameters of particles and on that basis the calculation of suspended sediment concentration is possibleLet's emphasize the basic advantages of back scattering acoustic gauges usage: – Obtaining the particles sizes and concentration distribution profiles is possible; – The initial granulometric structure of bottom sediments can be unknown (at use of several frequencies). The following can be referred to some lacks of the device: – The system should be calibrated in laboratory conditions; – In a positive feedback conditions the iterative computing process can converge to zero or to infinity. In this case experiments with a variation of carrier frequencies chosen for the analysis allow partially solve the problem (say experiments with different frequencies pairs, as 2/1 of MHz or 4/2 MHz).

Sign in / Sign up

Export Citation Format

Share Document