Research On Airflow Field Quality Assessment Of Full-service Deck Ship Based On CFD

The full development of the modern shipbuilding industry has made the safety of ship navigation becomes the focus of research by experts and scholars.When the ship sails in the ocean,the complex and varied ocean environment,the ship own structure and the take-off and landing of the carrier-based aircraft will cause the ship surface flow environment to become chaotic.For the existing safety question of ship deck flow field environment and the carrier-based aircraft take-off and landing,the simple numerical simulation method cannot make a specific assessment of the ship flow field environment under different working conditions,so we need to consider both qualitative and quantitative aspects,the appropriate sorting method is used to make evaluation on the ship deck flow field and the quality of the ship apron flow field.In this paper,the combination of theoretical analysis and numerical simulation is used to study the anphibious landing ship of the "Wasp-class".Firstly,numerical calculations are carried out on the deck flow field of rotorcraft and rotorless ship,and the flow field parameters of the amphibious landing ship under different wind speed and wind direction conditions are obtained.Secondly,nine qualitative and quantitative indicators for evaluating the flow field are selected by establishing a ship deck flow field evaluation system.Calculate the weight value of each evaluation index by using Analytic Hierarchy Process(AHP).Then using the TOPSIS method,the Relative Entropy Decision method and the Multi-Attribute Utility Theory(MAUT)three sorting methods to sort the flow field quality of the rotorless ship deck,and compare with numerical simulation results.Determine the relatively optimal sorting method and analyze the flow field quality of the six aprons on the deck surface of the rotorless ship.Evaluating the various areas of the deck of the ship after increasing the rotor on the apron 4 by using a relatively optimal sorting method.At the same time,the results are compared with the results of the sorting without rotorcraft.And the corresponding numerical cloud map is given to analyze the extreme points in the evaluation results.Finally,in order to study the distri-bution of the internal flow field mass of the apron after adding the rotor on the No.4 apron,change the key point selection rules in the aprons No.3,No.4 and No.5 and the weight value distribution of each index.Comparing changes in the mass distribution of the three aprons after changing the key position and index weight value.Research indicates:The results of the three methods for the flow field quality of the ship deck are relative wind speed 5m/s>relative wind speed 15m/s>relative wind speed 23m/s,However,the evaluation results of the TOPSIS method are more perfect;paying attention to the overall flow field of the ship deck.,the evaluation result of the TOPSIS method is related to the selection of the key points.The key points are selected in the research focus area,and the evaluation results will be more accurate.Winds under different conditions have the same effect on the flow field quality of the same area on the deck of rotorless ship and rotorship;Whether or not there is a rotor,the flow field in the deck of the ship has a fixed overall law.Changing the position of the key points or the index weight value will not have a large impact on the flow field quality in the apron.