Research On The Inflatable Deployment Process Of The Floating Platform

At present,the development of marine emergency evacuation system for domestic offshore platforms is still in its infancy.The floating platform is an important part of the life-saving module in the system,and the efficiency and stability of inflatable deployment have been paid close attention by researchers in related fields.During the release process of the system,the floating platform is automatically inflated,which is affected by the interfaces of other modules of the system and the external fluid field.Therefore,the research on the stability,feasibility and efficiency of the platform expansion has become a technical difficulty in the process of system deployment.This paper studies the inflatable development process of the floating platform in the marine emergency evacuation system,and an experiment is carried out to verify the quality and efficiency of the numerical results.In this paper,CV method and CPM method,which are relatively common algorithms in the field of inflation,are selected for preliminary discussion.According to ls-dyna solution,the characteristics of the two algorithms in the process of inflation expansion are compared,and the algorithm consistent with the actual situation is selected as the key word setting of inflatable deployment.According to the expansion requirements of boarding platform,it was determined that the floating platform should be folded scientifically and effectively when installed in the marine emergency evacuation system.Therefore,PRIMER is used for initial folding of floating platform.According to the difference of folding line and folding direction,this paper established partial folding form,"Z" type folding form and inner spiral folding form,and conducted numerical simulation of inflation process.Each gasbag on the floating platform has a gas inlet,so the gas should flow to both sides to fill the annular gasbag.Comparing the synchronicity of inflating on both sides of the three numerical results,it is observed whether inflating is stable.Considering the mutual influence of the two gasbags,the motion characteristics of the two gasbags are observed.The deployment efficiency of the platform will affect the deployment efficiency of the marine emergency evacuation system.Therefore,it is necessary to explore a scheme of floating platform with short inflation time.First of all,the inflating time of partial folding form,"Z" type folding form and inner spiral folding form is compared,and the interaction between the two gasbags is considered.The gas inlet of the two gasbags is arranged at a certain angle,and finally a floating platform scheme with the shortest inflating time and the best expansion stability is determined.According to the numerical results,it was determined that the inner spiral folding floating platform with opposite gas inlet is the optimal scheme,and the scheme is verified by static inflation,and the inflation time is determined.According to the fluid-solid coupling theory,a fluid-solid coupling model based on LS-PrePost is established for deploying the floating platform in the fluid domain,and the key words such as pretreatment setting in the fluid domain are introduced in detail.In the fluid domain,the velocity is 0,and the influence of viscosity coefficient is considered.DYNA solution is used to determine the characteristics and duration of each stage of floating platform deployment.According to the prototype experiment of the marine emergency evacuation system,the unfolded stage,duration and full deployment state of the floating platform are determined.By comparing the experimental results with the numerical simulation results,the deployment characteristics of each stage of the inflatable deployment process of the floating platform are analyzed.