scholarly journals LANDSLIDE-GENERATED TSUNAMIS: A NUMERICAL ANALYSIS OF THE NEAR-FIELD

2020 ◽  
pp. 8
Author(s):  
Alessandro Romano ◽  
Javier L. Lara ◽  
Gabriel Barajas ◽  
Benedetto Di Paolo ◽  
Giorgio Bellotti ◽  
...  
Keyword(s):  
Numerical Modelling ◽  
Numerical Study ◽  
Near Field ◽  
Experimental Tests ◽  
Wave Runup ◽  
Cfd Modelling ◽  
Tsunami Propagation ◽  
Tsunami Risk ◽  
Triggering Mechanisms ◽  
Landslide Triggering

There are coastal areas which are particularly prone to landslide-generated tsunami risk. The destructive effects caused by the impulsive waves, generated by landslide sources, can be strongly magnified by the characteristics of the so-called "confined geometries" (e.g. bays, reservoirs, lakes, volcanic islands, fjords, etc.). Complicated physical phenomena (e.g. trapping mechanisms, edge waves, wave runup, etc.) take place as a consequence of the interaction between the generated waves and the local bathymetry and control the tsunami propagation and interaction with the coast, often causing devastating consequences. Many past events of landslide-generated tsunamis testify this reality (e.g. Lituya Bay, Alaska, Fritz et al., 2009; Stromboli Island, Italy, Tinti et al., 2005; Anak Krakatau, Indonesia, Grilli et al., 2019). To reduce and mitigate the tsunami risk a proper comprehension, and modelling, of such complicated phenomena is crucial. Landslide-generated tsunamis have been largely studied by exploiting experimental, analytical and numerical modelling. Experimental tests are often time and money consuming, especially if 3D models are considered. Large facilities, as well as complicated experimental configurations and sophisticated measurement systems (e.g. Romano et al. 2016), are often needed. Furthermore, not always it is possible to explore in detail the influence of all the involved parameters, in particular those related to the landslide triggering mechanisms and rheology, that have a considerable influence on the wave characteristics in the so-called "near-field". To this end, numerical modelling can provide a valuable assistance. The new tools offered by the Computational Fluid Dynamics (CFD) methods represent a valuable means for shedding light on the unresolved aspects. In particular, the 3D CFD modelling techniques appear to be crucial as far as the tsunami characteristics in the near-field, induced by landslide sources, are concerned. Indeed, the accurate reproduction of the energy transfer between the landslide and the water is essential to model the tsunami generation and propagation mechanisms, allowing to explore a large variety of landslide triggering mechanisms and rheology. In this paper we present a numerical study of the landslide-generated tsunamis in the near-field.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/liUdiV2qXPg

Numerical study on near-field characteristics of landslide-generated impulse waves in channel reservoirs

2021 ◽  
Vol 595 ◽  
pp. 126012
Author(s):  
Xiaoliang Wang ◽  
Chuanqi Shi ◽  
Qingquan Liu ◽  
Yi An
Keyword(s):  
Numerical Study ◽  
Near Field ◽  
Impulse Waves

scholarly journals Monitoring Transepidermal Water Loss and Skin Wettedness Factor with Battery-Free NFC Sensor

Sensors ◽  
2020 ◽  
Vol 20 (19) ◽  
pp. 5549
Author(s):  
Syed Muhammad Ali ◽  
Wan-Young Chung
Keyword(s):  
Water Loss ◽  
Near Field ◽  
Experimental Tests ◽  
Transepidermal Water Loss ◽  
Comfort Level ◽  
Skin Wettedness ◽  
Moisture Content Level ◽  
Indoor And Outdoor Environments ◽  
Skin Moisture

The transepidermal water loss (TEWL) and the skin wettedness factor (SWF) are considered parts of a key perspective related to skincare. The former is used to determine the loss of water content from the stratum corneum (SC), while the latter is used to determine the human skin comfort level. Herein, we developed two novel approaches: (1) determination of the TEWL and the SWF based on a battery-free humidity sensor, and (2) the design of a battery-free smart skincare sensor device tag that can harvest energy from a near field communication (NFC)-enabled smartphone, making it a battery-free design approach. The designed skincare device tag has a diameter of 2.6 cm and could harvest energy (~3 V) from the NFC-enabled smartphone. A series of experimental tests involving the participation of eight and six subjects were conducted in vivo for the indoor and outdoor environments, respectively. During the experimental analysis, the skin moisture content level was measured at different times of the day using an android smartphone. The TEWL and SWF values were calculated based on these sensor readings. For the TEWL case: if the skin moisture is high, the TEWL is high, and if the skin moisture is low, the TEWL is low, ensuring that the skin moisture and the TEWL follow the same trend. Our smart skincare device is enclosed in a 3D flexible design print, and it is battery-free with an android application interface that is more convenient to carry outside than other commercially available battery-based devices.

Numerical Investigation of Ductile Fracture in Pipelines Under Complex Loading Using a Phenomenological Damage Model

2021 ◽  
Author(s):  
Iago S. Santos ◽  
Diego F. B. Sarzosa
Keyword(s):  
Ductile Fracture ◽  
Mechanical Response ◽  
Numerical Study ◽  
Damage Model ◽  
Stress Triaxiality ◽  
Numerical Procedure ◽  
Complex Loading ◽  
Experimental Tests ◽  
Compact Tension ◽  
Axial Tensile

Abstract This paper presents a numerical study on pipes ductile fracture mechanical response using a phenomenological computational damage model. The damage is controlled by an initiation criterion dependent on the stress triaxiality and the Lode angle parameter, and a post-initiation damage law to eliminate each finite element from the mesh. Experimental tests were carried out to calibrate the elastoplastic response, damage parameters and validate the FEM models. The tested geometries were round bars having smooth and notched cross-section, flat notched specimens under axial tensile loads, and fracture toughness tests in deeply cracked bending specimens SE(B) and compact tension samples C(T). The calibrated numerical procedure was applied to execute a parametric study in pipes with circumferential surface cracks subjected to tensile and internal pressure loads simultaneously. The effects of the variation of geometric parameters and the load applications on the pipes strain capacity were investigated. The influence of longitudinal misalignment between adjacent pipes was also investigated.

A Two-Region Model for Gradient Modification of Salt-Gradient Solar Ponds by Radial Injection

1996 ◽  
Vol 118 (1) ◽  
pp. 37-44 ◽  
Author(s):  
G. A. Eghneim ◽  
S. J. Kleis
Keyword(s):  
Turbulence Model ◽  
Field Model ◽  
Numerical Study ◽  
Numerical Models ◽  
Domain Boundary ◽  
Near Field ◽  
Solar Ponds ◽  
Numerical Predictions ◽  
Region Model ◽  
Salt Gradient

A combined experimental and numerical study was conducted to support the development of a new gradient maintenance technique for salt-gradient solar ponds. Two numerical models were developed and verified by laboratory experiments. The first is an axisymmetric (near-field) model which determines mixing and entrainment in the near-field of the injecting diffuser by solving the conservation equations of mass, momentum, energy, and salt. The model assumes variable properties and uses a simple turbulence model based on the mixing length hypothesis to account for the turbulence effects. A series of experimental measurements were conducted in the laboratory for the initial adjustment of the turbulence model and verification of the code. The second model is a one-dimensional far-field model which determines the change of the salt distribution in the pond gradient zone as a result of injection by coupling the near-field injection conditions to the pond geometry. This is implemented by distributing the volume fluxes obtained at the domain boundary of the near-field model, to the gradient layers of the same densities. The numerical predictions obtained by the two-region model was found to be in reasonable agreement with the experimental data.

CFD modelling of near-field dam break flow

2019 ◽  
pp. 47-60
Author(s):  
S. Esmaeeli Mohsenabadi ◽  
M. Mohammadian ◽  
I. Nistor ◽  
H. Kheirkhah Gildeh
Keyword(s):  
Near Field ◽  
Dam Break ◽  
Cfd Modelling ◽  
Dam Break Flow

scholarly journals HARBOUR DESIGN INCLUDING SEDIMENTOLOGICAL PROBLEMS USING MAINLY NUMERICAL TECHNICS

1980 ◽  
Vol 1 (17) ◽  
pp. 132 ◽  
Author(s):  
B. Latteux
Keyword(s):  
Continuity Equation ◽  
Numerical Study ◽  
Numerical Models ◽  
Near Field ◽  
Step Method ◽  
Access Channel ◽  
Load Transport ◽  
Erosion Area ◽  
Bed Load Transport ◽  
Water Height

For most of the needed studies for the design of Calais harbour enlargement works, the "Laooratoire National d'Hydraulique" chose to use numerical models. This approach includes the determination of currents around and insiae the new outer-haroour, just as the evaluation of the project sedimentologic impact and of the long-term evolution of a bank nameo "le Riaen de ia Rade", edging the access channel. Current studies were performed using four nested bidimensionnal computer models fitted on field data and supplying in eac;i point the depth-averaged velocity and the total water height. These four models are based on an implicite finite difference fractionnal step method. Besides for the very near field model the method is especially elaborated to enable' the detailed reproduction of eddies and flow separations. The sedimentological numerical study is based upon current models results : the bed-load transport is computed from the depth-averaged velocity and the water height previously determined using an empirical formula, and tne continuity equation applied to this loaa transport gives then the bed evolution. As soon as the depth variation is significant enough to react on the flow pattern, current fielos are readjusted oy a simple metnod based on flow continuity equation. This numerical model, applied to the near fielo, has given an evaluation of the sedimentological impact of the haroour enlargement project : - strong erosion in front of the new harbour due to current strengthening ; - accretion on each side of this erosion area, especially in the channel ; - bar formation at the harbour entrance.

Sign in / Sign up

Export Citation Format

Share Document