Calculation And Analysis Of Ice Load Under CFD-DEM Coupling

Sea ice cover and thickness in Arctic waters have been shrinking continuously in the past 40 years.This trend has facilitated the passage of ships in the Arctic and the development and utilization of the region.As the shortest waterway connecting the northern Pacific Ocean with the northern Atlantic Ocean,this navigation through the Arctic can save about 40% of the voyage compared with the current Suez-Panama Canal channel.In addition,Arctic oil and gas reserves are abundant,with 25% of the world's unexplored oil resources.Therefore,it is necessary to study the sea ice adaptability of ships and other structures working in this area.The external environment encountered by ships working in the ice area and other marine structures is mainly the coupled system of sea ice and wind,wave and current.For this coupling system,this paper uses FLUENT and EDEM software by coupling CFD with DEM,establish a numerical ice pool to study the structures' sea ice adaptability,the main work is as follows:(1)Establishment of numerical ice pools.Firstly,using the discrete element theory and python language to generate the program of the sea ice discrete element model under the arrangement of hexagonal arrays is compiled.Secondly,based on CFD-DEM coupling theory and EDEM-FLUENT coupling interface,the generated sea ice discrete element model is coupled with FLUENT flow field to establish a numerical ice pool.(2)Calibration of the parameters of the sea ice discrete element model.Using the program of sea ice discrete element generation,the mechanical properties of the generated sea ice discrete element model were measured by uniaxial compression experiment and three-point bending numerical experiment.These data are compared with the real sea ice mechanics data measured in the Bohai Sea,and the relationship between the Micro-Parameters used in the process of building the model by the discrete element software and the macro-mechanical characteristics of the model as a whole is analyzed.On this basis,a discrete element sea ice model with real sea ice mechanics characteristics is constructed for calculation.(3)Ice adaptability analysis of Sandglass-type FPSO.After the establishment of a real sea ice numerical model and the completion of the numerical ice pool,the Sandglass-type FPSO is applied in this paper for calculation.By comparing and analyzing the calculation results of Sandglass-type FPSO and Sevan Piranema,the performance advantages of Sandglass-type FPSO in the marine environment of ice area are determined.Ice load is an important control load in the marine environment of ice area.So far,no reasonable theoretical and computational model has been established.Traditionally,prototype observation and experimental methods are the main means of research,but the cost of these two methods is high,so an effective numerical method is needed to study them.Aiming at the problem of ice load in ice area,this paper presents a numerical calculation method by coupling CFD with DEM,establishes a real sea ice model and a numerical ice pond,and studies the ice resistance of Sandglass-type FPSO by using this method.This research on ice load in ice area has a good application value.