The Experts below are selected from a list of 1539 Experts worldwide ranked by ideXlab platform
Nicolas Beaudoin - One of the best experts on this subject based on the ideXlab platform.
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Zebra rocks: compaction waves create ore deposits
Scientific Reports, 2017Co-Authors: Ulrich Kelka, Manolis Veveakis, Daniel Koehn, Nicolas BeaudoinAbstract:Nature has a range of distinct mechanisms that cause initially heterogeneous systems to break their symmetry and form patterns. One of these patterns is zebra dolomite that is frequently hosting economically important base metal mineralization. A consistent generic model for the genesis of these periodically banded rocks is still lacking. In this contribution, we present for the first time a fully consistent mathematical model for the genesis of the pattern by coupling the reactive fluid-solid system with Hydromechanics. We show that visual banding develops at a given stress and host-rock permeability indicating that the wavelength and occurrence of the pattern may be predictable for natural settings. This finding offers the exciting possibility of estimating conditions of formation of known deposits as well as forecasting potential exploration targets.
Huijsmans R.h.m. - One of the best experts on this subject based on the ideXlab platform.
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Low-aspect ratio appendages for wind-assisted ships
'Springer Science and Business Media LLC', 2021Co-Authors: Van Der Kolk N.j., Keuning J.a., Huijsmans R.h.m.Abstract:Wind propulsion for commercial ships has been identified as a key component in the energy transition for the maritime industry. The sailing hybrid ship will operate with leeway (drift) angles to produce a lateral force known as sideforce, for steady operation under sail. In this paper, experimental results for the sailing performance of ships fitted with bilge keel appendages are presented. Systematic variations in appendage height, length, and position were tested, including several special cases (multiple bilge keels). The appendage typology is shown to mitigate the strong ‘destabilizing’ yaw moment that is characteristic of wind-assisted commercial vessels and to promote the non-linear sideforce component. The working principal for bilge keels—promotion of flow separation—can be employed to specify the separation location for components of the vessel vortex wake to improve the sailing performance of the ship.Ship Hydromechanics and Structure
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Efficient methodology of roll load prediction on 2D bodies in nonlinear flows
IWWWFB, 2018Co-Authors: Gadi Ratnakar, Huijsmans R.h.m., Van 't Veer A.p.Abstract:Ship Hydromechanics and StructuresMarine and Transport Technolog
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Experimental and numerical investigation on the heel and drift induced hydrodynamical loads of a high speed craft
FAST Organizing Committee, 2017Co-Authors: Bonci M., Keuning J.a., De Jong Pepijn, Van Walree Frans, Renilson Martin, Huijsmans R.h.m.Abstract:In order to provide an insight into the manoeuvring of high speed crafts, an experimental study was undertaken at the towing tank of Delft University of Technology, using a rescue vessel of the Royal Netherlands Sea Rescue Institution (KNRM).Ship Hydromechanics and Structure
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An absorbing boundary condition for free surface water waves
'Elsevier BV', 2017Co-Authors: Duz B., Wellens P.r., Borsboom M.j.a., Veldman A.e.p., Huijsmans R.h.m.Abstract:In this paper, the use of an absorbing boundary condition (ABC) is investigated for the numerical simulation of free surface water waves. An enhanced type of an ABC based on the first- and second-order Higdon boundary conditions is presented. The numerical implementation of the ABC using a staggered grid arrangement is explained in detail. Numerical examples are provided to demonstrate the performance of the proposed boundary conditions.Accepted Author Manuscript Part of special issue: Ninth International Conference on Computational Fluid Dynamics (ICCFD9)Ship Hydromechanics and Structure
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An analysis method to evaluate the added resistance in short waves considering bow wave breaking
2016Co-Authors: Choi B., Huijsmans R.h.m.Abstract:A bow wave breaking is one of the most prominent factors to be considered regarding the nonlinearity of added resistance for a ship. Considering the stability of the bow wave breaking, which is mostly influenced by the ship speed and the waterline entrance angle, can enhance understanding of the nonlinearity. Understanding of the nonlinearity can be improved by considering the stability of the bow wave breaking, which is mostly influenced by the ship speed and the waterline entrance angle. New transfer function containing the ship speed is proposed to make a better representative of the nonlinearity. This method is evaluated with the model test data of the Fast Displacement Ship (FDS) under the short waves condition (λ/L= 0.4). This study has shown that new transfer function can be an efficient analysis method of the ship performance prediction offering intuitive consistency with proposed residual resistance concept. The findings lead to better understanding the nonlinearity considering bow wave breaking.Ship Hydromechanics and Structure
Ulrich Kelka - One of the best experts on this subject based on the ideXlab platform.
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Zebra rocks: compaction waves create ore deposits
Scientific Reports, 2017Co-Authors: Ulrich Kelka, Manolis Veveakis, Daniel Koehn, Nicolas BeaudoinAbstract:Nature has a range of distinct mechanisms that cause initially heterogeneous systems to break their symmetry and form patterns. One of these patterns is zebra dolomite that is frequently hosting economically important base metal mineralization. A consistent generic model for the genesis of these periodically banded rocks is still lacking. In this contribution, we present for the first time a fully consistent mathematical model for the genesis of the pattern by coupling the reactive fluid-solid system with Hydromechanics. We show that visual banding develops at a given stress and host-rock permeability indicating that the wavelength and occurrence of the pattern may be predictable for natural settings. This finding offers the exciting possibility of estimating conditions of formation of known deposits as well as forecasting potential exploration targets.
Srikanth Vedantam - One of the best experts on this subject based on the ideXlab platform.
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Hydromechanics in dentine role of dentinal tubules and hydrostatic pressure on mechanical stress strain distribution
Dental Materials, 2007Co-Authors: Anil Kishen, Srikanth VedantamAbstract:Abstract Objectives This investigation is to understand the role of free water in the dentinal tubules on the mechanical integrity of bulk dentine. Methods Three different experiments were conducted in this study. In experiment 1, three-dimensional models of dentine with gradient elastic modulus, homogenous elastic modulus, and with and without hydrostatic pressure were simulated using the finite element method. Static compressive loads of 15, 50 and 100 N were applied and the distribution of the principal stresses, von Mises stresses, and strains in loading direction were determined. In experiment 2, experimental compression testing of fully hydrated and partially dehydrated dentine (21 °C for 72 h) was conducted using a Universal testing machine. In experiment 3, Fourier transform infrared spectroscopic analysis of hydrated and partially dehydrated dentine was carried out. Results The finite element analysis revealed that the dentine model with simulated hydrostatic pressure displayed residual tensile stresses and strains in the inner region adjacent to the root canal. When external compressive loads were applied to the model, the residual stresses and strains counteracted the applied loads. Similarly the hydrated specimens subjected to experimental compression loads showed greater toughness when compared to the partially dehydrated specimens. The stress at fracture was significantly higher in partially dehydrated specimens ( p = 0.014), while the strain at fracture was significantly higher in hydrated dentine specimens ( p = 0.037). Significance These experiments highlighted the distinct role of free water in the dentinal tubules and hydrostatic pressure on the stress–strain distribution within the bulk dentine.
Digby D Macdonald - One of the best experts on this subject based on the ideXlab platform.
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prediction of corrosion fatigue crack growth rate in alloys part ii effect of electrochemical potential nacl concentration and temperature on crack propagation in aa2024 t351
Corrosion Science, 2019Co-Authors: Danyil Kovalov, Balazs Fekete, George R Engelhardt, Digby D MacdonaldAbstract:Abstract We report here on the prediction of corrosion fatigue crack growth rate (CFCGR) for Aluminum Alloy 2024-T351 in aqueous environments under cyclical sinusoidal loading. Using the General Corrosion Fatigue Model (GCFM) described in Part I, the CFCGR was calculated as a function of environmental variables, including the electrochemical potential, NaCl concentration, loading frequency, stress intensity factor range, and temperature, in addition to the contribution from mechanical fatigue. Based on the influence of the environment, the changes in the potential drop down the crack enclave and the corrosion current density in a 1:1 electrolyte were also calculated from which the CFCGR was estimated. Corrosion fatigue crack growth in this alloy is readily understood in terms of the competition between environmental factors as described by the differential aeration hypothesis and the Hydromechanics (advection) of the system resulting from the cyclical opening and closing of the crack.
