Numerical Simulation of the Mechanical Structure of a Helmet Motorcyclist

2013 ◽  
Vol 856 ◽  
pp. 368-372 ◽  
Author(s):  
Bessai Naïma ◽  
Boudjemaa Fatiha ◽  
Lounis Mourad ◽  
Baumgartner Danie
Keyword(s):  
Numerical Simulation ◽  
Kinetic Energy ◽  
Road Safety ◽  
Main Function ◽  
Dynamic Reaction ◽  
Modern Life ◽  
High Importance ◽  
Protective System ◽  
Shock Impact ◽  
The Impact

Road safety is of high importance in our modern life in terms of social and economic. The helmet is the head protective system the most common used. Their main function is to reduce or prevent damage that may occur during an impact due to an accident. The head will be better protected if the more important quantity of the energy caused by the kinetic energy of the impact is absorbed by the helmet. The greater part of the impact energy should be absorbed by the deformations of the different layers of the helmet. The analytic equations of the model of the helmet parts show a realistic dynamic reaction of the different layers after the shock impact. These results will permit a better comprehension of the helmet behaviour to violent impact and the energy distribution in the different layers so a better optimisation of the head helmet in the future.

Based Fluent Study of Rotary Stream for Sand Reclamation Equipment

2015 ◽  
Vol 741 ◽  
pp. 486-489
Author(s):  
Wen Long Lu ◽  
Shan Li ◽  
Ying Luo ◽  
Qiang Chen
Keyword(s):  
Numerical Simulation ◽  
Kinetic Energy ◽  
Basic Structure ◽  
Velocity Control ◽  
Turbulent Model ◽  
Discrete Phase Model ◽  
Discrete Phase ◽  
Sand Movement ◽  
The Impact ◽  
Movement Tracking

The basic structure and principles of rotary stream for sand reclamation device will be introduction. According to the principle of renewable rotary stream for sand reclamation equipment, combination with Fluent numerical simulation model to construct the old sand regeneration process. And according to the impact velocity control problem for sand, using discrete phase model and turbulent model, the sand movement tracking and turbulent kinetic energy and the blowpipe of equipment were analyzed, finally puts forward some suggestions for improvement.

Numerical Simulation of Hypervelocity Impact on Mesh Bumper Causing Fragmentation and Ejection

2012 ◽  
Vol 525-526 ◽  
pp. 401-404
Author(s):  
Gong Shun Guan ◽  
Rui Tao Niu
Keyword(s):  
Numerical Simulation ◽  
Kinetic Energy ◽  
Impact Angle ◽  
Hypervelocity Impact ◽  
Impact Position ◽  
Debris Cloud ◽  
Combination Mode ◽  
The Impact ◽  
The Relationship ◽  
Aluminum Mesh

In order to study the fragmentation of projectile and ejection of debris clouds caused by hypervelocity impacting mesh bumper, simulation of aluminum sphere projectile hypervelocity normal impacting aluminum mesh bumper was practiced with SPH arithmetic of LS-DYNA soft. The diameter of projectile was 4mm. Impact velocities of aluminum spheres were varied between 2.2km/s and 6.2km/s. The impact angle was 0°. The relationship between the debris clouds characteristic of projectile and the impact position on aluminum mesh bumper was studied. The effect on fragmentation of projectile from different combination mode of aluminum mesh bumper was analyzed. The results showed that the morphologies of the debris cloud varied with the impact position when a projectile impacted the mesh bumper. The debris clouds as palpus was found, and some local kinetic energy concentrated appeared in the debris clouds. Debris clouds distribution was more uniform when projectile impacted wire across point on the mesh bumper. Debris clouds had more diffuse area and less residual kinetic energy when mesh bumper was combined with interleaving mode. Mesh bumper combined with interleaving mode was helpful in enhancing the protection performance of shields.

scholarly journals 8A.007 Evaluating the impact of a road safety education project in Madagascar schools

2021 ◽  
Author(s):  
Paolo Perego ◽  
Federica Biassoni ◽  
Ana Luisa Silva ◽  
Sam Clark ◽  
Jesse Randrianarisoa
Keyword(s):  
Road Safety ◽  
Safety Education ◽  
Education Project ◽  
The Impact

scholarly journals A New Method to Determine the Impact of Individual Field Quantities on Cycle-to-Cycle Variations in a Spark-Ignited Gas Engine

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4136
Author(s):  
Clemens Gößnitzer ◽  
Shawn Givler
Keyword(s):  
Kinetic Energy ◽  
Flow Field ◽  
Turbulent Kinetic Energy ◽  
Negative Impact ◽  
Operating Conditions ◽  
Engine Operation ◽  
Gas Engine ◽  
Cycle Simulation ◽  
Simulation Results ◽  
The Impact

Cycle-to-cycle variations (CCV) in spark-ignited (SI) engines impose performance limitations and in the extreme limit can lead to very strong, potentially damaging cycles. Thus, CCV force sub-optimal engine operating conditions. A deeper understanding of CCV is key to enabling control strategies, improving engine design and reducing the negative impact of CCV on engine operation. This paper presents a new simulation strategy which allows investigation of the impact of individual physical quantities (e.g., flow field or turbulence quantities) on CCV separately. As a first step, multi-cycle unsteady Reynolds-averaged Navier–Stokes (uRANS) computational fluid dynamics (CFD) simulations of a spark-ignited natural gas engine are performed. For each cycle, simulation results just prior to each spark timing are taken. Next, simulation results from different cycles are combined: one quantity, e.g., the flow field, is extracted from a snapshot of one given cycle, and all other quantities are taken from a snapshot from a different cycle. Such a combination yields a new snapshot. With the combined snapshot, the simulation is continued until the end of combustion. The results obtained with combined snapshots show that the velocity field seems to have the highest impact on CCV. Turbulence intensity, quantified by the turbulent kinetic energy and turbulent kinetic energy dissipation rate, has a similar value for all snapshots. Thus, their impact on CCV is small compared to the flow field. This novel methodology is very flexible and allows investigation of the sources of CCV which have been difficult to investigate in the past.

scholarly journals Driver Liability Assessment in Vehicle Collisions in Spain

2021 ◽  
Vol 18 (4) ◽  
pp. 1475
Author(s):  
Almudena Sanjurjo-de-No ◽  
Blanca Arenas-Ramírez ◽  
José Mira ◽  
Francisco Aparicio-Izquierdo
Keyword(s):  
Road Safety ◽  
Accurate Estimation ◽  
Main Hypothesis ◽  
Self Organizing Maps ◽  
Safety Measures ◽  
Vehicle Collisions ◽  
Promising Tool ◽  
Visual Clustering ◽  
Open Question ◽  
The Impact

An accurate estimation of exposure is essential for road collision rate estimation, which is key when evaluating the impact of road safety measures. The quasi-induced exposure method was developed to estimate relative exposure for different driver groups based on its main hypothesis: the not-at-fault drivers involved in two-vehicle collisions are taken as a random sample of driver populations. Liability assignment is thus crucial in this method to identify not-at-fault drivers, but often no liability labels are given in collision records, so unsupervised analysis tools are required. To date, most researchers consider only driver and speed offences in liability assignment, but an open question is if more information could be added. To this end, in this paper, the visual clustering technique of self-organizing maps (SOM) has been applied to better understand the multivariate structure in the data, to find out the most important variables for driver liability, analyzing their influence, and to identify relevant liability patterns. The results show that alcohol/drug use could be influential on liability and further analysis is required for disability and sudden illness. More information has been used, given that a larger proportion of the data was considered. SOM thus appears as a promising tool for liability assessment.

Hybrid nanofluid flow over a stretched cylinder with the impact of homogeneous–heterogeneous reactions and Cattaneo–Christov heat flux: Series solution and numerical simulation

Heat Transfer ◽  
2021 ◽  
Author(s):  
Anthonysamy John Christopher ◽  
Nanjundan Magesh ◽  
Ramanahalli Jayadevamurthy Punith Gowda ◽  
Rangaswamy Naveen Kumar ◽  
Ravikumar Shashikala Varun Kumar
Keyword(s):  
Numerical Simulation ◽  
Heat Flux ◽  
Series Solution ◽  
Heterogeneous Reactions ◽  
Hybrid Nanofluid ◽  
Nanofluid Flow ◽  
The Impact

Investigation on penetration model of shaped charge jet in water

2016 ◽  
Vol 30 (02) ◽  
pp. 1550268 ◽  
Author(s):  
Jinwei Shi ◽  
Xingbai Luo ◽  
Jinming Li ◽  
Jianwei Jiang
Keyword(s):  
Numerical Simulation ◽  
Theoretical Model ◽  
Model Simulation ◽  
Theoretical Models ◽  
Theoretical Research ◽  
Water Medium ◽  
Simulation Results ◽  
Jet Penetration ◽  
The Impact ◽  
Penetration Velocity

To analyze the process of jet penetration in water medium quantitatively, the properties of jet penetration spaced target with water interlayer were studied through test and numerical simulation. Two theoretical models of jet penetration in water were proposed. The theoretical model 1 was established considering the impact of the shock wave, combined with the shock equation Rankine–Hugoniot and the virtual origin calculation method. The theoretical model 2 was obtained by fitting theoretical analysis and numerical simulation results. The effectiveness and universality of the two theoretical models were compared through the numerical simulation results. Both the models can reflect the relationship between the penetration velocity and the penetration distance in water well, and both the deviation and stability of theoretical model 1 are better than 2, the lower penetration velocity, and the larger deviation of the theoretical model 2. Therefore, the theoretical model 1 can reflect the properties of jet penetration in water effectively, and provide the reference of model simulation and theoretical research.

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