scholarly journals An Investigation of Dynamic Responses and Head Injuries of Standing Subway Passengers during Collisions

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Yong Peng ◽  
Tuo Xu ◽  
Lin Hou ◽  
Chaojie Fan ◽  
Wei Zhou
Keyword(s):  
Numerical Simulation ◽  
Head Injury ◽  
Head Injuries ◽  
Dynamic Responses ◽  
Passive Safety ◽  
Friction Coefficients ◽  
Safety Design ◽  
Parametric Studies ◽  
Simulation Results ◽  
Set Up

With the development of the subway and the pressing demand of environmentally friendly transportation, more and more people travel by subway. In recent decades, the issues about passenger passive safety on the train have received extensive attention. In this research, the head injury of a standing passenger in the subway is investigated. Three MADYMO models of the different standing passenger postures, defined as baseline scenarios, are numerically set up. HIC15values of passengers with different postures are gained by systematic parametric studies. The injury numerical simulation results of various scenarios with different friction coefficients, collision acceleration, standing angle, horizontal handrail height, and ring handrail height are analyzed. Results show that the horizontal handrail provides better protection in the three different standing passenger postures. Different friction coefficients and the standing angle have great impact on the head injuries of passengers in three different scenarios. The handrail height also has some effects on head injury of passengers with different standing postures, so it is necessary to be considered when designing the interior layout of the subway. This study may provide guidance for the safety design of the subway and some advices for standing subway passengers.

Research on the Numerical Simulation of Silting in Floodplain and Scouting in Main Channel of Over-Bank Flooding in the Lower Yellow River

2011 ◽  
Vol 255-260 ◽  
pp. 3692-3696
Author(s):  
Xiao Lei Zhang ◽  
Dong Po Sun ◽  
Feng Ran Zhang
Keyword(s):  
Numerical Simulation ◽  
Mathematical Model ◽  
Yellow River ◽  
Main Channel ◽  
River Channel ◽  
Lower Yellow River ◽  
The Lower Yellow River ◽  
Water And Sediment ◽  
Simulation Results ◽  
Set Up

The 2-D water and sediment mathematical model which reflects silting in floodplain and scouting in main channel of over-bank flooding in the Lower Yellow River has been set up in this paper. Through carrying on 2-D water and sediment numerical simulation of the “96.8” typical flood, the author studied influence of over-bank flooding on flood travel and transverse exchange. The primary simulation results show that, adopting the over-bank flooding for silting in floodplain and scouting in main channel effectively guaranteed and expanded transverse exchange between floodplain and main channel and maintained the river channel vigor. This can relieve “secondary suspended river” states in the Low Yellow River to a certain extent; at the same time, the different magnitudes of over-bank floods have different effect of silting in floodplain and scouting in main channel.

Numerical Simulation on Hydrogen Dispersion in Automobiles due to Storage Cylinder Failure

2011 ◽  
Author(s):  
Yan-Lei Liu ◽  
Jin-Yang Zheng ◽  
Shu-Xin Han ◽  
Yong-Zhi Zhao
Keyword(s):  
Numerical Simulation ◽  
Finite Element Method ◽  
Finite Element ◽  
Numerical Model ◽  
Hydrogen Sensor ◽  
High Concentration ◽  
Concentration Region ◽  
Species Transport ◽  
Safety Design ◽  
Simulation Results

A numerical model for dispersion of hydrogen in hydrogen powered automobiles was established basing on finite element method with species transport and reaction module of FLUENT. And corresponding numerical simulations were done in order to analysis the dispersion of hydrogen due to leakage from different position of the storage cylinder on the automobiles. Also, the distribution of the hazard region due to hydrogen dispersion was obtained. The simulation results show that the baffle above the cylinder can accumulate the hydrogen. Therefore, the high concentration region of hydrogen exists near the baffle. The study can provide reference for hydrogen sensor placement and safety design of hydrogen powered automobiles.

Dynamic Responses of the State-of-the-Art Floating System Integrating a Wind Turbine With a Steel Fish Farming Cage: Model Tests vs. Numerical Simulations

2021 ◽  
Author(s):  
Yu Lei ◽  
Xiang Yuan Zheng ◽  
Hua-dong Zheng
Keyword(s):  
Numerical Simulation ◽  
Numerical Model ◽  
Wind Turbine ◽  
Fish Farming ◽  
Dynamic Responses ◽  
Drag Coefficients ◽  
Free Decay ◽  
Floating System ◽  
Simulation Results ◽  
Decay Tests

Abstract This work is dedicated to comparing the experimental and numerical results of the dynamic responses of a novel floating system integrating a floating offshore wind turbine with a steel fish farming cage (FOWT-SFFC) under wind and wave loadings. The patents of this floating system have been successfully licensed recently in China and USA. The experimental study is carried out in the Ocean Basin of Tsinghua Shenzhen International Graduate School, with a Froude scaling of 1:30. A small commercial wind turbine is used to produce the scaled wind loads on FOWT-SFFC in terms of the similarity of thrust force. In this paper, the setup of model tests is described first. Second, a numerical model of prototype FOWT-SFFC is built in the software OrcaFlex. Then, this numerical model is calibrated and updated by the results of free decay tests and static offset tests in the basin. The numerical model also adopts three sets of drag coefficients. Finally, the experimental results of FOWT-SFFC under a variety of load cases are presented and compared with the numerical simulation results. They include seakeeping tests for hydrodynamic motion response amplitude operators (RAOs) and dynamic responses corresponding to normal operating and survival conditions. The numerical simulation results show that, though they are in good agreement with model test data especially on time records of dynamic responses, they are sensitive to the selection of drag coefficients particularly on extreme values and low-frequency spectral contents. Appropriate drag coefficients are suggested to be used in the numerical model for a specific environmental condition. Drag coefficients benchmarked from the free decay tests may not be suitable for moderate and harsh wave conditions.

Design and Simulation Research on Mechanical Ventilation System for Small Underground Granary

2014 ◽  
Vol 875-877 ◽  
pp. 2148-2151
Author(s):  
Hai Hong Zhang ◽  
Zhong Ying Wang ◽  
Qiang Liu ◽  
Peng Fei Ma
Keyword(s):  
Numerical Simulation ◽  
Mechanical Ventilation ◽  
Pressure Field ◽  
Ventilation System ◽  
Simulation Research ◽  
New Type ◽  
Simulation Results ◽  
Dynamic Numerical Simulation ◽  
Set Up ◽  
Better Than

The mechanical ventilation system of new type underground granary was designed and three wind pipe models with different length were investigated in this paper. Dynamic numerical simulation was applied for evaluating the cooling effect of mechanical ventilation of the granary. The simulation results, including temperature field, flow field and pressure field results, show that the cone shaped base of grain granary is better than flat shaped base. It is an optimal project that the main wind pipe opens with mesh only in the bottom. In addition, four vertical guide plates were set up around the main wind pipe, which have the function of saving energy and reducing consumption.

scholarly journals Analytical report on post traumatic hydrocephalus

YMER Digital ◽  
2022 ◽  
Vol 21 (01) ◽  
pp. 144-147
Author(s):  
R Srinivas ◽  
◽  
Mohamed Naleer ◽  
Kishore Kumar ◽  
◽  
...  
Keyword(s):  
Head Injury ◽  
Ct Scan ◽  
Traffic Accidents ◽  
Road Traffic ◽  
Head Injuries ◽  
Clinical Analysis ◽  
Medical College ◽  
Fall From Height ◽  
Post Traumatic ◽  
Set Up

Post-traumatic hydrocephalus (PTH) is a field and disorder less explored in neurosurgery though we see many cases. The commonest causes in our set up includes head injury for which people have undergone decompressive craniectomies, severe head injuries with raised ICP. We did a clinical analysis on 23 cases in a period of 3 years duration from 2018 -2021. We did Evd in few cases for emergency purposes when there was decerebration and we went ahead with VP shunt in all the patients who had gross ventricular dilatation. We have projected our analytical report in these cases. METHODS A retrospective study was conducted in the Department of Neurosurgery in Sri Ramachandra medical college. The clinical outcome of patients diagnosed with PTH was studied. These cases were treated by surgery. The stastical analysis along with cause of the hydrocephalus with the outcome in pre and postoperative period were studied. RESULTS Among the 23 patients studied 82% were males. Road traffic accident was the main cause of injury. The other main cause was a fall from height. Assault was another reason for head injuries which we recorded. We found all road traffic accidents were only because of bike riders either pillion or the people driving the vehicle. . Craniotomy was done in 50 % of the patients, 90 % of the patients recovered who had a gcs of 13 to 7. People with gcs lss than 7 were intubated recovery rate was 7.5 %. . There was 100%mortality because of primary head injury in all the patients who had brain stem contusions with dilated pupil. CONCLUSIONS Trauma to head and who were operated had the highest incidence of post tramatic head injury. Smaller the decompressive craniectomies had symptomatic post traumatic head ache with post traumatic hydrocephalus.. CT scan of the brain is considered the choice of investigation toearly diagnose PTH.we even analysed the ct scan and found when there was periventricular lucency the patient outcome after VP shunting is good. KEY WORDS Hydrocephalus, Head Injury, Trauma

Transient Numerical of Piston Wind in Subway Station

2014 ◽  
Vol 644-650 ◽  
pp. 467-470
Author(s):  
Hai Tao Bao
Keyword(s):  
Fluid Dynamics ◽  
Numerical Simulation ◽  
Aerodynamic Characteristic ◽  
Navier Stokes ◽  
Subway Station ◽  
Practical Application ◽  
Virtual Design ◽  
Computational Fluid Dynamics Cfd ◽  
Simulation Results ◽  
Set Up

Computational Fluid Dynamics (CFD) is used for the investigation of the piston wind. The Navier-Stokes (N-S) equations and standard turbulence model were applied to set up the model. The train transient aerodynamic characteristic has been research during the crossing process. The simulation results are trustworthy and numerical simulation of piston wind is feasible using dynamic grid in CFD software, which provides the basis for the virtual design of piston wind. It is significant importance for further studying the structure of train, shorten its development and guiding significance for practical application.

Numerical Simulation of Ozone Oxidation on Oily Wastewater

2011 ◽  
Vol 71-78 ◽  
pp. 2721-2726
Author(s):  
Meng Fu Zhu ◽  
Cheng Deng ◽  
Xiu Dong You ◽  
Hong Bo Su ◽  
Ping Chen
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Oil Content ◽  
Simulation Method ◽  
Pollutant Removal ◽  
Oily Wastewater ◽  
Theory Analysis ◽  
Reaction Equation ◽  
Simulation Results ◽  
Set Up

A simulation method was presented based on the theory analysis and ozone reaction equation. The preliminary mathematical models of ozonation correlative to oily pollutant removal were set up by numerical simulation. The ozonation models implied removal ratio of oil related to reaction time, ozone dosage and initial oil content. The simulation results were consistent with the experimental data.

Occupant Dynamic Responses for Evaluation of Compliance Characteristics of Aircraft Bulkheads

1992 ◽  
Author(s):  
Hamid M. Lankarani ◽  
Deren Ma ◽  
Rajiv Menon
Keyword(s):  
Head Injury ◽  
Contact Force ◽  
Head Injuries ◽  
Element Model ◽  
Dynamic Responses ◽  
Instrument Panel ◽  
Force Model ◽  
Sled Test ◽  
Contact Force Model ◽  
Head Injury Criteria

Abstract One important aspect of aircraft crashworthiness studies is to reduce head injuries to an aircraft occupant in case of a head contact with its surroundings. In view of the significance of this problem, studies of post-crash dynamic behavior of victims and the compliance characteristics of the aircraft bulkhead are necessary in order to reduce severe head injuries. Crash dynamics program SOM-LA/TA, incorporating a dynamic model of the human body with a finite element model of the seat structure was used. Modifications including development of more accurate contact force models and an occupant/seat envelope were performed in SOM-LA/TA. It was then used as an analytical tool for determination of the occupant response and the compliance characteristics of the bulkhead in various crash environments. Correlated studies of analytical simulations with impact sled test results were accomplished. It was observed that the code reasonably predicted the Head-Injury-Criteria (HIC) for the triangular-shaped pulses. A parametric study of the coefficients in the contact force model was then performed in order to obtain a correlation between the HIC and the coefficients in the contact force model. A measure of optimal values for the bulkhead compliances and displacement requirements was thus achieved in order to keep the possibility of head injury as little as possible. This information could in turn be used in the selection of suitable materials for the bulkhead, instrument panel, or interior walls of an aircraft.

Numerical Simulation and Experimental Research on Pedestal Looseness of a Rotor System

2007 ◽  
Author(s):  
Hui Ma ◽  
Hong Liang Yao ◽  
Zhao Hui Ren ◽  
Feng Wen ◽  
Bang Chun Wen
Keyword(s):  
Numerical Simulation ◽  
Mechanical Model ◽  
Test Rig ◽  
Rotating Speed ◽  
Runge Kutta Method ◽  
Motion State ◽  
Simulation And Experiment ◽  
State Changes ◽  
Simulation Results ◽  
Set Up

The mechanical model of looseness of fastening bolt on the bearing pedestal is set up based on the project practice. Using the nonlinear oil-film model put forward by Adiletta, the dynamic characteristics were investigated by numerical Runge-Kutta method. At last, the experiment is performed to investigate the pedestal looseness by a test rig and the fault signals are analyzed by the spectrum cascade and reassigned wavelet scalogram. Numerical simulation and experiment all show that system motion state changes frequently with the increase of the rotating speed. And the experimental results coincide with the simulation results.

scholarly journals Effects of Bedding Geometry and Cementation Strength on Shale Tensile Strength Based on Discrete Element Method

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Jiong Wang ◽  
Yang Wang ◽  
Liu Yang ◽  
Tianquan Chang ◽  
Qingping Jiang
Keyword(s):  
Mechanical Properties ◽  
Numerical Simulation ◽  
Tensile Strength ◽  
Softening Effect ◽  
Strength Based ◽  
Increasing Trend ◽  
Simulation Results ◽  
Set Up ◽  
Brazilian Splitting ◽  
Line Crack

To study the effects of anisotropy and heterogeneity on the shale failure mode and tensile strength, Brazilian splitting tests were performed from both directions of the bedding and layer thickness. Layers containing different bedding and loading angles and layer thicknesses were obtained separately. The results show that, at 0° and 90° angles, the shale cracks grow “linearly”; at 15°, the shale cracks have “arc type” growth; and at 30°–75°, the shale-splitting displays “broken line” crack propagation. The tensile strength from 0° to 90° exhibits an increasing trend. Water has a significant softening effect on the tensile strength of shale—the higher the water content, the lower the tensile strength. In addition, a 3DEC numerical simulation was used to simulate the tests, establishing shale specimen particles with random blocks. In the shale disc, uneven parallel bedding and uniform parallel bedding were set up with different loading angles and layer thicknesses to generate simulated stress-displacement curves, and the effect of layering on shale cleavage was analyzed from a mesoscopic perspective. The tensile strength of shale with uniform parallel bedding was found to be higher under the same conditions, which is consistent with the experimental results. By comparing the experimental and simulation results, from both the macro- and mesoperspectives, the Brazilian splitting crack growth of shale is affected by bedding, displaying a process from disorder to order. This study is of great significance for further exploration of the mechanical properties of shale under loading failure.

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