Study On Ship Cabin Fire Simulation And Visualization Application

With the rapid development of the global economy,the number of vessels in the world continues to increase.At the same time,the incidence of ship accidents at home and abroad is still high,among which ship-fire accidents occupy a higher proportion of ship-disasters,causing huge property losses and casualties.Therefore,the International Maritime Organization has put forward the requirement of giving full attention to firefighting skills of crew.Due to the particularity of the ship’s fire,the crew could not experience the real fire scene and could not understand the development of the ship-fire so that its fire-fighting skill is hard to be improved.Aiming at the above problems,it is proposed to apply the ship fire mechanism as a theoretical basis to the visualization process of cabin fires,build a visualization system of ship cabin fires based on fire simulation calculations.The system is run on a head-mounted virtual reality terminal to provide an immersive cabin fire experience and thus be used in crew fire training to enhance crew awareness of cabin fire developments and to make up for the inability to conduct large-scale fire simulations in existing fire drills,at the same time,providing a technical basis for immersion fire training systems The object of study is a bulk carrier,the mathematic model of ship cabin fire is established basing on large eddy simulation,the emphasis is put on modeling and simulation of ship cabin space,the simulation data is also analyzed to summarize the law of fire spread.Combined with the law of motion of particles and the law of fire diffusion,the fire visualization system is built under the virtual reality engine Unity3 D.The final test results of system show that the ship cabin fire visualization system combining fire simulation data can provide a more realistic scene of fire spread,meanwhile,with the virtual reality terminal to make the operation more immersive.The main work is as follows:(1)Large-eddy simulation is taken as the basis of mathematical model,and the combustion model and heat radiation model of marine cabin are established.Taking bulk carrier as the research object,combined with the layout of the cabin,the mechanical equipment and piping in the cabin are reasonably simplified.The simulation model is established under PyroSim fire simulation software.Determine the calculation area of the simulation model as well as the grid scale,and set the parameters of the fire source and the boundary conditions.The reliability of the mathematical model and the simulation model is verified by comparing the data obtained from the actual fire experiment and the corresponding simulation experiment.(2)According to the data obtained from the PyroSim simulation platform,the rainbow plot of the temperature in slice,the comparison chart of the thermocouple measured data,and the gas concentration data plot were analyzed,and draw out of the rule of the temperature of the smoke and the gas concentration of the cabin in the fire simulation process during the time and space.And the harm of the smoke generated during the fire to the human body is briefly described.(3)The virtual cabin scene is constructed by the virtual reality engine Unity3 D,the modeling of the equipment in the cabin is completed by using the modeling software,the scene is optimized and optimized by bump mapping and light map baking technique,The detection function and the navigation grid baking component bake the walkable area in the cabin scene and complete the route transfer.(4)Combining with the related motion rules to realize the visualization process of fire particles and firewater,reading the simulation data file from PyroSim,completing the dynamic display of the simulation data corresponding to the location point and the visualization of the spread of fire and flue gas,Using Photon Server to manage screen synchronization between multiple clients,complete visualization system of the entire cabin fire,and publish to head-mounted virtual reality terminal.The system is open to relevant professional students to experience and test,get better feedback.