Evacuation route optimization under real-time toxic gas dispersion through CFD simulation and Dijkstra algorithm

2022 ◽  
pp. 104733
Author(s):  
Jiyun Wang ◽  
Xiaoyang Yu ◽  
Ruowen Zong ◽  
Shouxiang Lu
Keyword(s):  
Real Time ◽  
Cfd Simulation ◽  
Route Optimization ◽  
Dijkstra Algorithm ◽  
Gas Dispersion ◽  
Toxic Gas ◽  
Evacuation Route

scholarly journals CFD simulation of gas-liquid floating particles mixing in an agitated vessel

2017 ◽  
Vol 23 (3) ◽  
pp. 377-389 ◽  
Author(s):  
Liangchao Li ◽  
Bin Xu
Keyword(s):  
Velocity Field ◽  
Cfd Simulation ◽  
Solid Phase ◽  
Fluid Model ◽  
Surface Region ◽  
Operating Conditions ◽  
Gas Dispersion ◽  
Agitated Vessel ◽  
Superficial Gas Velocity ◽  
Floating Particles

Gas dispersion and floating particles suspension in an agitated vessel were studied numerically by using computational fluid dynamics (CFD). The Eulerian multi-fluid model along with standard k-? turbulence model was used in the simulation. A multiple reference frame (MRF) approach was used to solve the impeller rotation. The velocity field, gas and floating particles holdup distributions in the vessel were first obtained, and then, the effects of operating conditions on gas dispersion and solid suspension were investigated. The simulation results show that velocity field of solid phase and gas phase are quite different in the agitated vessel. Floating particles are easy to accumulate in the center of the surface region and the increasing of superficial gas velocity is in favor of floating particles off-surface suspension. With increasing solids loading, the gas dispersion becomes worse, while relative solid holdup distribution changes little. The limitations of the present modeling are discussed and further research in the future is proposed.

MISSION-ADAPTABLE ROUTE PLANNING IN UNCERTAIN AND ADVERSARIAL ENVIRONMENT

2006 ◽  
Vol 15 (05) ◽  
pp. 803-821 ◽  
Author(s):  
PING YAN ◽  
MINGYUE DING ◽  
CHANGWEN ZHENG
Keyword(s):  
Real Time ◽  
A Priori ◽  
Route Planning ◽  
Optimal Solution ◽  
Dijkstra Algorithm ◽  
Solution Quality ◽  
Model Complex ◽  
Local Methods ◽  
Domain Specific Knowledge ◽  
Planning Algorithm

In this paper, the route-planning problems of Unmanned Aerial Vehicle (UAV) in uncertain and adversarial environment are addressed, including not only single-mission route planning in known a priori environment, but also the route replanning in partially known and mission-changeable environments. A mission-adaptable hybrid route-planning algorithm based on flight roadmap is proposed, which combines existing global and local methods (Dijkstra algorithm, SAS and D*) into a two-level framework. The environment information and constraints for UAV are integrated into the procedure of building flight roadmap and searching for routes. The route-planning algorithm utilizes domain-specific knowledge and operates in real time with near-optimal solution quality, which is important to uncertain and adversarial environment. Other planners do not provide all of the functionality, namely real-time planning and replanning, near-optimal solution quality, and the ability to model complex 3D constraints.

scholarly journals An Evacuation Route Model of Crowd Based on Emotion and Geodesic

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Bangquan Liu ◽  
Zhen Liu ◽  
Dechao Sun ◽  
Chunyue Bi
Keyword(s):  
Real Time ◽  
Geometric Constraints ◽  
Crowd Density ◽  
Time Simulation ◽  
Critical Issues ◽  
Particle Hydrodynamics ◽  
Crowd Evacuation ◽  
Dense Crowd ◽  
Evacuation Route ◽  
Real Time Simulations

Making unconventional emergent plan for dense crowd is one of the critical issues of evacuation simulations. In order to make the behavior of crowd more believable, we present a real-time evacuation route approach based on emotion and geodesic under the influence of individual emotion and multi-hazard circumstances. The proposed emotion model can reflect the dynamic process of individual in group on three factors: individual emotion, perilous field, and crowd emotion. Specifically, we first convert the evacuation scene to Delaunay triangulation representations. Then, we use the optimization-driven geodesic approach to calculate the best evacuation path with user-specified geometric constraints, such as crowd density, obstacle information, and perilous field. Finally, the Smooth Particle Hydrodynamics method is used for local avoidance of collisions with nearby agents in real-time simulation. Extensive experimental results show that our algorithm is efficient and well suited for real-time simulations of crowd evacuation.

Computational Fluid Dynamic Modelling of High Aspect Ratio Cross-Sectional Jets I: The Effect of Orifice Shape on Jet Behaviour

2003 ◽  
Author(s):  
Sarah J. Wakes
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Cfd Simulation ◽  
Fluid Dynamic ◽  
Dynamic Modelling ◽  
Common Belief ◽  
Cross Sectional ◽  
Numerical Work ◽  
Hydrocarbon Production ◽  
Gas Dispersion

High aspect ratio cross-sectional jets (HAR jets) are significant for many industrial applications including offshore hydrocarbon production safety, manufacturing processes, aeronautics and others. Little interest has been paid to such jets as the common belief was that within an acceptable distance from the jet orifice the behaviour emulates that of an axisymmetric jet. Previous experimental and preliminary numerical work [1–4] has shown that this is not necessarily correct. Work has been done to investigate numerically the effect the orifice shape has on the behaviour of the jets. This will be in terms of the curvature of the orifice in comparison to the same aspect ratio with a straight rectangular shape. Simulations have been carried out relating to experimental work [1] as comparison and verification. The spreading of the jet will be assessed as it can have significance in terms of safety, performance and effectiveness. This work enhances previous work [3] and allows an assessment of whether such a curvature in the inlet significantly effects the jet behaviour for two pipe pressures. The choice of turbulence model will also be assessed in terms of the standard two-equation k-ε model and it’s variants the RNG and Realisable models. Later work will investigate the use of Large Eddy Simulation within the context of the geometry used here. This important information will allow for greater understanding for the modelling of such jets in a CFD simulation within a complex industrial problem such as gas dispersion with a hydrocarbon production area. It is realized that the fluid does not emerge as a single velocity from the pipe into the flange and hence to form the inlet for the jet. Therefore the effect of the flow within the pipe and how this effects the emerging jet behaviour is investigated in part II of this paper [5].

IoT-based real time intelligent routing for emergent crowd evacuation

2019 ◽  
Vol 37 (3) ◽  
pp. 604-624
Author(s):  
Yanlan Mei ◽  
Ping Gui ◽  
Xianfeng Luo ◽  
Benbu Liang ◽  
Liuliu Fu ◽  
...  
Keyword(s):  
Decision Making ◽  
Real Time ◽  
Programming Model ◽  
Emergency Evacuation ◽  
Guidance System ◽  
Programming Approach ◽  
Metro Station ◽  
Content Type ◽  
Crowd Evacuation ◽  
Evacuation Route

Purpose The purpose of this paper is to take advantage of Internet of Things (IoT) for intelligent route programming of crowd emergency evacuation in metro station. It is a novel approach to ensure the crowd safety and reduce the casualties in the emergency context. An evacuation route programming model is constructed to select a suitable evacuation route and support the emergency decision maker of metro station. Design/methodology/approach The IoT technology is employed to collect and screen information, and to construct an expert decision model to support the metro station manager to make decision. As a feasible way to solve the multiple criteria decision-making problem, an improved multi-attributive border approximation area comparison (MABAC) approach is introduced. Findings The case study indicates that the model provides valuable suggestions for evacuation route programming and offers practical support for the design of an evacuation route guidance system. Moreover, IoT plays an important role in the process of intelligent route programming of crowd emergency evacuation in metro station. A library has similar structure and crowd characteristics of a metro station, thus the intelligent route programming approach can be applied to the library crowd evacuation. Originality/value The highlights of this paper are listed as followings: the accuracy and accessibility of the metro station’s real-time information are improved by integrating IoT technology with the intelligent route programming of crowd emergency evacuation. An improved MABAC approach is introduced to the expert support model. It promotes the applicability and reliability of decision making for emergency evacuation route selection in metro station. It is a novel way to combine the decision-making methods with practice.

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