Emergency Simulation And Visualization Of Oil Spill From Ship In Navigation Simulation

In recent years,oil spill accidents frequently occur at sea,and the threat of oil spills is increasingly severe.In order to enhance the ability of emergency disposal of oil spill at sea,it has become an urgent problem to strengthen the training of emergency disposal personnel for oil spill at sea.Simulator training for marine emergency simulation has proved to be a feasible method.But at present,the oil spill model in the simulator is generally lack of realistic be-havior,and the interaction is not flexible enough.Therefore,this thesis proposes a fluid simu-lation method to simulate oil spill at sea,which can further enhance the realistic behavior in the simulation of oil spill.At the same time,GPU is utilized to solve the time consuming problems in parallel and to realize the real-time physical-based interactive simulation of off-shore oil spill.The research work in this thesis can be summarized as the following items:1.A method of interaction between fluid and moving obstacle based on NBFLIP(Narrow Band Fluid Implicit Particle)is proposed,which solves the problem that previous NBFLIP methods can not deal with the interaction with moving obstacles.Physical-based fluid simula-tion is based on NS(Navier-Stokes)equations,combined with the basic theory of partial dif-ferential equations,applying finite difference method in solving the NS equations discretely.This is the main idea for physical-based fluid simulation.Fluid and obstacle interaction can obtain very rich fluid results,so fluid simulation is often combined with obstacle interaction.However,the traditional NBFLIP method can not deal with the interaction of moving obsta-cles,so it can not deal with the interactive simulation of oil spill and moving oil boom.In this thesis,a new method of complex obstacle discretization based on Signed Distance Function(SDF)is proposed,and the boundary conditions of moving obstacles are derived.The NBFLIP method is used to simulate the interaction of moving obstacles.The application of NBFLIP method is further extended.2.The NBFLIP-VOF multiphase flow simulation method is proposed to solve the prob-lem that traditional NBFLIP method is not suitable for multiphase flow simulation.Marine oil spill involves the interaction of various fluids.In order to further enhance the reality of oil spill simulation,the NBFLIP-VOF method is proposed to simulate oil spill at sea.In the framework of NBFLIP fluid simulation,VOF multiphase flow model is used to simulate oil spill at sea.Due to the strong dissipation of the previous numerical schemes with first order accuracy,the solution of VOF model equations is easy to diverge.The VOF equation is nu-merically solved by using the second-order total variation Diminishing(TVD)scheme,and the oil spill is numerically simulated by introducing a Super-Bee flux limiter.Finally,the validation of volume fraction convection in shear flow field,the validation of oil boom inter-action experiment based on VOF model,and the Rayleigh-Taylor instability benchmark ex-periment of multiphase flow are carried out to verify the reliability of the method.3.A physical-based real-time interactive simulation method for offshore oil spill is pro-posed and implemented.The key time-consuming problems in the simulation of offshore oil spill are accelerated in parallel by GPU,which solves the computational efficiency of the in-teractive simulation of offshore oil spill in the real-time system.The parallel discrete interac-tive method of complex obstacles based on SDF method and the parallel visualization method of oil spill on sea surface based on texture projection method are proposed.The parallel ac-celeration of these time-consuming computational problems lays the foundation for the re-al-time simulation and interactive system for offshore oil spill.Combined with the parallel solution of NS equation based on GPU acceleration,the physical-based real-time simulation and interaction of marine oil spill are realized.In this thesis,a physical-based real-time fluid simulation and interaction method for oil spill is proposed.Combining with the fluid simulation based on NS equation and the theory of multiphase flow,the boundary conditions of moving obstacles based on NBFLIP method are analyzed and deduced.A multiphase flow simulation method based on NBFLIP method is proposed,which is greatly improved by GPU parallel acceleration.The efficiency of fluid simulation calculation is improved.Finally,the reliability of this method is verified by a pro-totype system.