scholarly journals A physical simulation method for tsunami inundation flow with arbitrary flow velocity and inundation depth

2013 ◽  
Vol 69 (2) ◽  
pp. I_1471-I_1475
Author(s):  
Kazuyuki OTA ◽  
Naoto KIHARA ◽  
Takahiro SATO ◽  
Daisuke TAKABATAKE ◽  
Masafumi MATSUYAMA ◽  
...  
Keyword(s):  
Flow Velocity ◽  
Physical Simulation ◽  
Simulation Method ◽  
Tsunami Inundation ◽  
Inundation Depth ◽  
Arbitrary Flow

Numerical study of the aerodynamic and power characteristics of the cycloidal rotor, under incoming flow

2019 ◽  
pp. 25-34
Author(s):  
Александр Анатольевич Дектерев ◽  
Артем Александрович Дектерев ◽  
Юрий Николаевич Горюнов
Keyword(s):  
Flow Velocity ◽  
Numerical Study ◽  
Lift Coefficient ◽  
Simulation Method ◽  
Aerodynamic Characteristics ◽  
Incoming Flow ◽  
Ansys Fluent ◽  
Energy Characteristics ◽  
Power Characteristics ◽  
Calculation Results

Исследование направлено на разработку и апробацию методики численного моделирования аэродинамических и энергетических характеристик циклоидального ротора. За основу взята конфигурация ротора IAT21 L3. Для нее с использованием CFD-пакета ANSYS Fluent построена математическая модель и выполнен расчет. Проанализировано влияние скорости набегающего потока воздуха на движущийся ротор. Математическая модель и полученные результаты исследования могут быть использованы при создании летательных аппаратов с движителями роторного типа. This article addresses the study of the aerodynamic and energy characteristics of a cycloidal rotor subject to the influence of the incoming flow. Cycloidal rotor is one of the perspective devices that provide movement of aircrafts. Despite the fact that the concept of a cycloidal rotor arose in the early twentieth century, the model of a full-scale aircraft has not been yet realized. Foreign scientists have developed models of aircraft ranging in weight from 0.06 to 100 kg. The method of numerical calculation of the cycloidal rotor from the article [1] is considered and realized in this study. The purpose of study was the development and testing of a numerical simulation method for the cycloidal rotor and study aerodynamic and energy characteristics of the rotor in the hovering mode and under the influence of the oncoming flow. The aerodynamic and energy characteristics of the cycloidal rotor, rotating at a speed of 1000 rpm with incoming flow on it with velocities of 20-80 km/h, were calculated. The calculation results showed a directly proportional increase of thrust with an increase of the incoming on the rotor flow velocity, but the power consumed by the rotor was also increased. Increase of the incoming flow velocity leads to the proportional increasing of the lift coefficient and the coefficient of drag. Up to a speed of 80 km/h, an increase in thrust and power is observed; at higher speeds, there is a predominance of nonstationary effects and difficulties in estimating the aerodynamic characteristics of the rotor. In the future, it is planned to consider the 3D formulation of the problem combined with possibility of the flow coming from other sides.

scholarly journals Numerical Simulation of Tsunami Inundation in Urban Areas

2006 ◽  
Vol 1 (1) ◽  
pp. 148-156 ◽  
Author(s):  
Tetsuya Hiraishi ◽  
◽  
Tomohiro Yasuda ◽  
Keyword(s):  
Numerical Simulation ◽  
Numerical Model ◽  
Simulation Model ◽  
Urban Areas ◽  
Tokyo Bay ◽  
Tsunami Inundation ◽  
Model City ◽  
Inundation Depth ◽  
The Pacific ◽  
Potential Damage

The population and property in urban areas facing waterfronts is rapidly increasing together with the probability that a huge tsunami will occur on the Pacific Rim. The huge potential damage reflects the need to develop a highly accurate simulation model for tsunami inundation to help mitigate tsunami effects. We developed a simulation model to estimate the inundation depth and speed of tsunamis in urban areas. The model was applied to calculate the vari- ation of inundation areas in a model city facing Tokyo Bay. Experiments of tsunami inundation in the model city on a 1/50 scale was carried out for validation of the numerical model.

Numerical Study on Spatial Correlation Characteristics of Tsunami Inundation Depth

2020 ◽  
Author(s):  
Yo Fukutani
Keyword(s):  
Risk Assessment ◽  
Spatial Correlation ◽  
Numerical Study ◽  
Material Strength ◽  
Initial Water ◽  
Earthquake Parameters ◽  
Tsunami Inundation ◽  
Inundation Depth ◽  
Fault Parameters ◽  
Tsunami Risk

<p>For a probabilistic tsunami risk assessment of multiple sites, it is important to consider the spatial correlation between tsunami inundation depth and the sites because it affects the aggregated probability distribution of site damages. Various uncertainties such as ground motion, building response characteristics, and material strength are considered in the probabilistic seismic risk assessment. However, any research that evaluates the spatial correlation characteristics of tsunamis is yet to be reported. In this study, we evaluate the macro spatial correlation coefficient of the tsunami inundation depth according to the relative distance in the tsunami run-up region. We firstly constructed the fault parameters of the Sagami trough earthquake which has a large slip off the Kanto area in Japan. The moment magnitude of the earthquake is 8.7, and there are 6,149 small faults. Using the initial water level calculated from the earthquake parameters as input data, we solved the continuous equation and 2D linear long wave equation, targeting Zushi city, Kanagawa Prefecture. The maximum tsunami inundation depth was 8.71 m. We regressed the exponential function (<em>ρ(x) = aexp(bx) + cexp(dx)</em>) for the relationship between the distance from the coastline and the tsunami inundation depth. As a result, we obtained an evaluation formula with a relatively high accuracy. The coefficient were a = 0.4555, b = −0.1653, c = 0.5434, d = −0.007345 and the determination coefficient was 0.992. The results of this study can be used for a probabilistic tsunami risk assessment for multiple sites.</p>

Structural Analysis of Selected Failures Caused by the 27 February 2010 Chile Tsunami

2012 ◽  
Vol 28 (1_suppl1) ◽  
pp. 215-243 ◽  
Author(s):  
Ian Robertson ◽  
Gary Chock ◽  
Juan Morla
Keyword(s):  
Flow Velocity ◽  
Structural Performance ◽  
Structural Element ◽  
Local Flow ◽  
Inundation Depth ◽  
Hydrodynamic Loading ◽  
Tsunami Damage ◽  
Chile Earthquake ◽  
Chile Tsunami ◽  
Loading Estimates

Following the 2010 Chile earthquake and tsunami, the authors participated in the EERI reconnaissance team that traveled to Chile to document damage and structural performance. The authors focused on tsunami damage following the earthquake. A summary of tsunami damage to structures is given. Based on a series of well-defined structural element failures at sites where inundation depth was measured, the team was able to evaluate the hydrodynamic loading required to cause these failures and derive estimated lower bound flow velocity overland during the event. It was estimated that the velocity exceeded 3.2 m/s in Talcahuano harbor and 4.3 m/s in the coastal town of Dichato. When found in proximity to damaged buildings and other larger structures of interest, these simple structures can serve as “flow surrogate instruments” to estimate the local flow velocity. Failure analysis of these simple structures indicated that the hydrodynamic loading estimates provided by FEMA P646 may be unconservative.

scholarly journals A Multicomponent Thermal Fluid Numerical Simulation Method considering Formation Damage

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Xinan Yu ◽  
Xiaoping Li ◽  
Shuoliang Wang ◽  
Yi Luo
Keyword(s):  
Numerical Simulation ◽  
Oil Recovery ◽  
Heavy Oil ◽  
Physical Simulation ◽  
Damage Model ◽  
Simulation Method ◽  
Formation Damage ◽  
Thermal Fluids ◽  
Before And After ◽  
Control Equation

Multicomponent thermal fluid huff and puff is an innovative heavy oil development technology for heavy oil reservoirs, which has been widely used in offshore oilfields in China and has proved to be a promising method for enhancing oil recovery. Components of multicomponent thermal fluids contain many components, including carbon dioxide, nitrogen, and steam. Under high temperature and high pressure conditions, the complex physical and chemical reactions between multicomponent thermal fluids and reservoir rocks occur, which damage the pore structure and permeability of core. In this paper, the authors set up a reservoir damage experimental device, tested the formation permeability before and after the injection of multiple-component thermal fluids, and obtained the formation damage model. The multicomponent thermal fluid formation damage model is embedded in the component control equation, the finite difference method is used to discretize the control equation, and a new multielement thermal fluid numerical simulator is established. The physical simulation experiment of multicomponent thermal fluid huff and puff is carried out by using the actual sand-packed model. By comparing the experimental results with the numerical simulation results, it is proved that the new numerical simulation model considering formation damage proposed in this paper is accurate and reliable.

Simulation and Prototyping of an Orbital Lightning Detector

2020 ◽  
pp. 4-17
Author(s):  
V.E. Kvitka
Keyword(s):  
High Speed ◽  
Physical Simulation ◽  
Simulation Method ◽  
Low Earth Orbit ◽  
High Speed Camera ◽  
Atmospheric Physics ◽  
Target Environment ◽  
Detector Simulation ◽  
Background Brightness ◽  
Exterior Design

The problem of detecting lightning flashes from space is becoming more and more important as the remote sensing of Earth, climatology and atmospheric physics develop. Orbital lightning detectors are designed both in Russia and abroad. The paper considers the problem of mathematical and physical simulation of a high-speed camera designed to observe lightning flashes from onboard spacecraft in low Earth orbit. Our previous works substantiated the exterior design of the lightning detector, computed its properties and described the algorithms behind the software. In order to validate the design results, we need to prototype the instrument. We describe the main problems of detecting lightning flashes as observed from space. We show a computer simulation method producing snapshots that takes into account the interference generated by the background and the photodetector. We studied the problems of recreating the target environment during prototyping of the lightning detector, accounting for the properties of the phenomenon observed, that is, the flash spot dimensions and the ratio of the background brightness to that of the lightning. We describe the principle of comparing these two types of snapshots (taken by the prototype and synthesised by the software) and compared the results of processing the images obtained. The results matched, which allowed us to validate the snapshot processing algorithm and confirmed that the lightning detector simulation method developed is correct

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