Hydrodynamic Performance Research On The Fire-fighting Vessel And Its Propellers

Fire-fighting vessels are the collective names of ships used for firefighting operations.Fire-fighting vessels not only need to provide fire-fighting assistance to ships suffering fire disaster,but also need to perform rescue work on coastal ports,oil depots and other coastal facilities.When the accident happens,the fire-fighting vessel must arrive at the scene as soon as possible to rescue and constantly change the maneuvering state to respond to the fire.Therefore,the fire-fighting ship has high requirements for rapidity and maneuverability.The research on the hydrodynamic performance of fire-fighting vessels cannot be considered only from the ship itself.The performance of ships and their propellers must also be fully considered.The interaction between ships and propellers will affect the rapidity and maneuverability of ships.With the continuous development of computer technology and CFD method,the numerical simulation results of ship hydrodynamic performance based on CFD method have been verified.However,the ship models used by previous research are mostly standard ship models such as KCS and KVLCC2.This article is based on CFD method to carry out the research on the hydrodynamic performance such as the rapidity and maneuverability of Dalian NO.2 fire-fighting ship and its propellers.This article takes the Dalian No.2 fire-fighting ship and its MAU 5-blade propeller as the research object.After three-dimensional modeling of fire-fighting ship and its propellers with Catia software.Star-CCM+ software is used to solve the hydrodynamic performance of the ship and its propeller based on the RANS equation solving method.In the analysis process,the Realizable k-? turbulent model was used to simulate the viscous fluid flow,the VOF method to simulate the free liquid surface,and the sliding grid method to simulate the propeller rotation.Firstly,the resistance forecast of Dalian No.2 fire-fighting vessel and the analysis of propeller open-water performance are completed.Based on the results of the above mentioned,the self-propulsion performance of ship design speed is analyzed.The self-propulsion point of the fire-fighting boat is confirmed by changing the rotation speed of the propeller and selfpropulsion factors such as advancing fraction,thrust deduction and so on are obtained.After confirming the rotation speed of the propeller at ship design speed,the hydrodynamic performance of the single ship and hull-propeller interaction with different drift angles is analyzed.The resistance,lateral force,yaw moment of the ship and the thrust,torque of the propeller at different drift angles are obtained.