scholarly journals EXTERNAL AND INTERNAL WAVE SET-UP AT POROUS PBA REVETMENTS ON A SAND FOUNDATION

2012 ◽  
Vol 1 (33) ◽  
pp. 27
Author(s):  
Gisa Foyer ◽  
Hocine Oumeraci
Keyword(s):  
Large Scale ◽  
Wave Length ◽  
Irregular Waves ◽  
Scale Model ◽  
Large Scale Model ◽  
Internal Set ◽  
Deep Water Wave ◽  
Set Up ◽  
The Stability ◽  
Almost All

Wave set-up is generally considered for the stability analysis of beaches, but not or not explicitly for the design of revetments. Based on large-scale model results with regular and irregular waves, it is shown in this paper that this is not justified. For this purpose, the wave set-up on a porous bonded revetment and the related internal set-up in the sand foundation below the revetment are analysed for different breaker types. The results particularly show that (i) considerable set-up values are obtained for almost all breaker types, (ii) a good correlation exists with the deep water wave length for both external and internal set-up and (iii) the internal set-up is significantly affected by the wave set-up on the slope. Empirical formulae for the prediction of the external and internal set-up are also proposed for both regular and irregular waves.

Large-Scale Experiments of Wave-Overtopping Loads on Walls: Layer Thicknesses and Velocities

2018 ◽  
Author(s):  
Lorenzo Cappietti ◽  
Irene Simonetti ◽  
Andrea Esposito ◽  
Maximilian Streicher ◽  
Andreas Kortenhaus ◽  
...  
Keyword(s):  
Large Scale ◽  
Scale Validation ◽  
Irregular Waves ◽  
Scale Model ◽  
Small Scale ◽  
Wave Loads ◽  
Wave Overtopping ◽  
Large Scale Model ◽  
Vertical Walls ◽  
Set Up

Wave-Overtopping loads on vertical walls, such as those located on top of a dike, have been investigated in several small-scale experiments in the past. A large-scale validation for a mild foreshore situation is still missing. Hence the WALOWA (WAve LOads on WAlls) experimental campaign was carried out to address this topic. This paper, first presents a description of the large-scale model, the measurement set-up and the experimental methodologies, then it focuses on the layer thicknesses and velocities of the flows created on the promenade by the wave overtopping. A set of resistive wave gauges, ultrasonic distance sensors and velocimeters have been used to conduct these measurements. Preliminary data analysis and results, related to a 1000 irregular waves long test, are discussed. The momentum flux of these flows is studied and its implications, for the wave-overtopping loads acting on the vertical walls, are highlighted.

Large scale model test investigation on wave run-up in irregular waves at slender piles

2013 ◽  
Vol 72 ◽  
pp. 69-79 ◽  
Author(s):  
J. Ramirez ◽  
P. Frigaard ◽  
T. Lykke Andersen ◽  
L. de Vos
Keyword(s):  
Model Test ◽  
Large Scale ◽  
Irregular Waves ◽  
Scale Model ◽  
Large Scale Model ◽  
Test Investigation ◽  
Run Up

scholarly journals Stability Analysis of Multiharmonic Nonlinear Vibrations for Large Models of Gas-Turbine Engine Structures With Friction and Gaps

2016 ◽  
Author(s):  
E. P. Petrov
Keyword(s):  
Gas Turbine ◽  
Large Scale ◽  
Frequency Domain Analysis ◽  
Gas Turbine Engine ◽  
Forced Response ◽  
Scale Model ◽  
Turbine Engine ◽  
Nonlinear Springs ◽  
Large Scale Model ◽  
The Stability

An efficient method is proposed for the multiharmonic frequency domain analysis of the stability for nonlinear periodic forced vibrations in gas-turbine engine structures and turbomachines with friction, gaps and other types of nonlinear contact interfaces. The method allows using large-scale finite element models for structural components together with detailed description of nonlinear interactions at contact interfaces between these components. The highly accurate reduced models are applied in the assessment of stability of periodic regimes for large-scale model of gas-turbine structures. An approach is proposed for the highly-accurate calculation of motion of a structure after it is perturbed from the periodic nonlinear forced response. Efficiency of the developed approach is demonstrated on a set of test cases including simple models and large-scale realistic bladed disc models with different types of nonlinearities: friction, gaps and cubic nonlinear springs.

Mineralogical investigations of the first package of the alternative buffer material test – I. Alteration of bentonites

Clay Minerals ◽  
2013 ◽  
Vol 48 (2) ◽  
pp. 199-213 ◽  
Author(s):  
S. Kaufhold ◽  
R. Dohrmann ◽  
T. Sandén ◽  
P. Sellin ◽  
D. Svensson
Keyword(s):  
Large Scale ◽  
Carbon Accumulation ◽  
Maximum Temperature ◽  
Material Test ◽  
Buffer Material ◽  
Set Up ◽  
One Year ◽  
The Stability ◽  
Iron Tube ◽  
Almost All

AbstractBentonite, which is envisaged as a promising engineered barrier material for the safe disposal of highly radioactive waste, was and is investigated in different large scale tests. The main focus was and is on the stability (or durability) of the bentonite. However, most countries concentrated on one or a few different bentonites only, regardless of the fact that bentonite performance in different applications is highly variable. Therefore, SKB (Svensk Kärnbränslehantering) set up the first large scale test which aimed at a direct comparison of different bentonites. This test was termed the ‘alternative buffer material test’ and considers eleven different clays which were either compacted (blocks) or put into cages to keep the material together. One so-called package consisted of thirty different blocks placed on top of each other. These blocks surrounded a heated iron tube 10 cm in diameter. Altogether three packages were installed in the underground test laboratory Äspö, Sweden. The first package was terminated 28 months after installation and the bentonite had been exposed for the maximum temperature (130°C) for about one year.Almost all geochemical and mineralogical alterations of the different bentonites (apart from exchangeable cations) were restricted to the contact between iron and bentonite. The increase of the Fe2O3 content was attributed to corrosion of the tube. However, the typical 7 or 14 Å smectite alteration product was not found. At the contact of one sample, siderite was precipitated. Some samples showed anhydrite and organic carbon accumulation and some showed dissolution of clinoptilolite and cristobalite. IR spectroscopy, XRD, and XRF data indicated the formation of trioctahedral minerals/domains in the case of some bentonites. Even more data has to be collected before unambiguous conclusions concerning both alteration mechanisms and bentonite differences can be drawn.

Large-Scale Investigations of Geotextile Sandcontainers Used for Scour Protection of Offshore Monopiles Supporting Wind Energy Turbines

2006 ◽  
Author(s):  
Joachim Gru¨ne ◽  
Uwe Sparboom ◽  
Reinold Schmidt-Koppenhagen ◽  
Zeya Wang ◽  
Hocine Oumeraci
Keyword(s):  
Large Scale ◽  
Research Programme ◽  
Scale Model ◽  
Research Centre ◽  
Large Wave ◽  
Wave Channel ◽  
Large Scale Model ◽  
First Results ◽  
The Stability ◽  
Scour Protection

An innovative scour protection for monopile structures was proposed by using geotextile sand containers in a research programme started recently. Large-scale model tests on the stability of such alternative scour protection are being performed in the Large Wave Channel (GWK) of the Coastal Research Centre (FZK). First results are reported from basic test series performed with single geotextile sand containers and container groups with different container weights, varied in sizes and percentages of filling. Further an empirical approach on the stability of sand containers is estimated as a first approximation from the results.

Large-Scale Model Investigation for Monopile Decommissioning of Offshore Wind Turbines: Overpressure and Vibratory Pile

2021 ◽  
Author(s):  
Nils Hinzmann ◽  
Patrick Lehn ◽  
Jörg Gattermann
Keyword(s):  
Large Scale ◽  
Planning Process ◽  
Complete Removal ◽  
Offshore Wind ◽  
Scale Model ◽  
Offshore Wind Turbines ◽  
Large Scale Model ◽  
First Results ◽  
Set Up ◽  
Large Scale Tests

Abstract As of now, only a small number of offshore foundations, related to offshore wind energy, were decommissioned in Europe. With a diameter up to nine meter, an embedment of about 40 meter and a set up effect over 25 years, the necessary force to pull the pile out of the seabed can be assumed, if at all determinable, to be enormous. The piles that were decommissioned were cut beneath the mud line, which leaves approximately one third of the foundation permanently in the seabed. Different methods and techniques for a complete removal of offshore pile foundation are currently investigated within the project DeCoMP. Vibratory extraction aims for a reduction of the pile skin friction by creating a layer of less density between the pile shaft and pending soil. During the design and planning process for vibratory installation or extraction a drivability prediction is a key element. In order to identify and characterize soil parameter for the numerical simulation of a drivability prediction, large-scale tests are performed by the Institute of Geomechanics and Geotechnics of the Technische Universität Braunschweig (IGG-TUBS) [1]. In this paper first results of pilot tests with two vibrators are presented and key elements such as crane uplift, frequency and acceleration displayed.

LARGE-SCALE MODEL STUDY ON SCOUR AROUND SLENDER MONOPILES INDUCED BY IRREGULAR WAVES

2009 ◽  
Author(s):  
Ulrike Prepernau ◽  
Joachim Grüne ◽  
Uwe Sparboom ◽  
Reinold Schmidt-Koppenhagen ◽  
Zeya Wang ◽  
...  
Keyword(s):  
Large Scale ◽  
Irregular Waves ◽  
Scale Model ◽  
Model Study ◽  
Large Scale Model

scholarly journals Stability Analysis of Multiharmonic Nonlinear Vibrations for Large Models of Gas Turbine Engine Structures With Friction and Gaps

2016 ◽  
Vol 139 (2) ◽  
Author(s):  
E. P. Petrov
Keyword(s):  
Gas Turbine ◽  
Large Scale ◽  
Frequency Domain Analysis ◽  
Gas Turbine Engine ◽  
Forced Response ◽  
Scale Model ◽  
Turbine Engine ◽  
Nonlinear Springs ◽  
Large Scale Model ◽  
The Stability

An efficient method is proposed for the multiharmonic frequency-domain analysis of the stability for nonlinear periodic forced vibrations in gas turbine engine structures and turbomachines with friction, gaps, and other types of nonlinear contact interfaces. The method allows using large-scale finite element models for structural components together with detailed description of nonlinear interactions at contact interfaces between these components. The highly accurate reduced models are applied in the assessment of stability of periodic regimes for large-scale model of gas turbine structures. An approach is proposed for the highly accurate calculation of motion of a structure after it is perturbed from the periodic nonlinear forced response. Efficiency of the developed approach is demonstrated on a set of test cases including simple models and large-scale realistic bladed disk models with different types of nonlinearities: friction, gaps, and cubic nonlinear springs.

RANCANG BANGUN PERANGKAT EKSPERIMENTASI PROSES PIROLISIS BIOMASA GELOMBANG MIKRO

2013 ◽  
Vol 14 (2) ◽  
Author(s):  
Noor Fachrizal
Keyword(s):  
Large Scale ◽  
Continuous Model ◽  
Biomass Energy ◽  
Scale Model ◽  
Small Scale ◽  
Laboratory Apparatus ◽  
Liquid Form ◽  
Large Scale Model ◽  
Bio Oil ◽  
Pyrolysis Of Biomass

Biomass such as agriculture waste and urban waste are enormous potency as energy resources instead of enviromental problem. organic waste can be converted into energy in the form of liquid fuel, solid, and syngas by using of pyrolysis technique. Pyrolysis process can yield higher liquid form when the process can be drifted into fast and flash response. It can be solved by using microwave heating method. This research is started from developing an experimentation laboratory apparatus of microwave-assisted pyrolysis of biomass energy conversion system, and conducting preliminary experiments for gaining the proof that this method can be established for driving the process properly and safely. Modifying commercial oven into laboratory apparatus has been done, it works safely, and initial experiments have been carried out, process yields bio-oil and charcoal shortly, several parameters are achieved. Some further experiments are still needed for more detail parameters. Theresults may be used to design small-scale continuous model of productionsystem, which then can be developed into large-scale model that applicable for comercial use.

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