| In recent years,the Arctic region has attracted more and more people’s attention.At present,polar ice-breaking equipment still has great limitations,so the air cushion ice-breaking platform has emerged through its excellent ice-breaking and carrying capacity.Researches on high-speed air cushion ice-breaking have been very advanced,and various simulation analyses on air cushion wave-breaking have been very complete,while researches on air-cushion ice-breaking platform using low-speed principle are still very few.The numerical simulation and model test of air cushion equipment in various navigation conditions have been sufficient,but there is no research on the operation of air cushion ice-breaking equipment in broken ice.On the basis of the above research,this paper will calculate the ice-breaking capacity of the air cushion ice-breaking platform.In this paper,the basic principles of numerical simulation are briefly introduced which includes CFD control equation,turbulence model,initial and boundary conditions and VOF method.After analyzing the lifting state of the air cushion platform,P_C—Q—h forms a stable balance during lifting.Based on the lifting principle of the air cushion platform,the platform is modeled to simulate the formation of air cavity at the bottom of the platform under the condition of ice and no ice in still water.By changing the air cushion pressure and air cushion size,the change of air cavity is analyzed.Then the relative position of ice and platform is changed to analyze the variation rule of air cavity of platform at different driving distance on ice.The air-cushion icebreaker breaks the ice at low speed,which is equivalent to standing still on the ice.It is lifted by P_C—Q—h with dynamic balance.According to the low-speed ice-breaking principle of the air cushion platform,part of the ice can be regarded as a cantilever beam,which loses the elastic support of water and is only under the action of ice gravity and air cushion pressure.STAR-CCM+was used to simulate the the air-cushion platform,and ice response under different conditions is studied.The ice-breaking capacity of the air cushion ice-breaking platform was also analyzed.The resistance of air cushion platform in broken ice is calculated,and the resistance of different working conditions are obtained by numerical simulation which is verified by formula and model test.The prediction of low speed ice breaking ability of air cushion platform is realized.Due to the design of the air cushion ice-breaking platform to considering ice breaking performance of both its economy at the same time,considering air cushion platform of ice breaking capacity research results and crushed ice in running resistance research results,multi-objective optimization of various parameters of air cushion platform is carried out.The optimization objective is ice breaking performance and resistance performance,and the optimization parameters are air cushion pressure and air cushion platform size.The response surface method was used to construct the mathematical model and draw the performance map of the air cushion ice-breaking platform with air cushion size,air cushion pressure,ice stress response,ice breaking capacity and ice breaking resistance.Finally the best design scheme was selected. |
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