Numerical Simulation On Heeling Angle Of Type Round Bilge Speedboat In Turning Motion

Numerical tank is A new method for ship performance by digital simulationcalculation in recent years，Numerical simulation of the environment diversity and varietyof solving technology is the key technology.In this paper，In order to study the property of the ship in rotary motion,the author usedifferent numerical model and hybrid finite volume method combined with the grid tosovle the Navier-Stokes equations．Discusses the parameters of different variables underthe stress of the rotary motion and fluid characteristics． Established unsteady numericaldiscrete calculation model and calculation method based on the hybrid grid.Writing theboundary conditions of numerical control functions，and analyzed the flow characteristics.The author analyzed round bilge speedboat by using of a large numerical calculationsoftware Fluent， Discusses the force and torque in rotary motion and flow fieldinformation.This paper adopted two kinds of methods for discussing numerical simulation ofrotary motion．The first one is based on the MRF method．The centrifugal and coriolisacceleration fluid is converted into the source term are added to the solution of equationsolution by coordinate transformation solution．The sailing speed of the round bilge boatis11.5kn, and13.5kn at full speed，So we chose33.5,4,4.5, and5times the radius ofgyration, captain and9,12,13,16and19kn and dip Angle is5,8,11,14,18degrees，total125models．Analysis under the different turning radius, speed and horizontal Angle ofthe ship and the changes of stress and heeling moment By numerical calculation．At thesame time by looking for specification，In the numerical simulation result of interpolationand through auxiliary construction methods to get relevant numerical calculation andcheck the real heeling Angle and standardize the size of the heeling Angle．Ａt the end ofthis chapter simply analyzes the authenticity of the results of numerical calculation and thelimitations of MRF method.The second is use the dynamic grid reconstruction technique to solve theNavier-Stokes equations in the fixed coordinates，Through simulation gradually achieve2dmodel in3d dynamic mesh model and the VOF model to realize the effect of rotary freewave． This model Can make up for in the first method can not simulate the free liquidsurface wave of faults．In the3d model, adjust irregular grid on the surface to the smoothsurface by using the method of smooth surface local area along with the movement ofbody．This method greatly ease the dynamic mesh grid model and node movement in thegrid quality change and VOF model for grid conflict between high quality requirements，And the rotary motion of six degrees of freedom of movement has carried on the simplediscussion, pointed out that the realization of the movement of the difficulties.at the sametime, the two common simulation of the rotary motion is simulatedin this paper，Throughmathematical principle and establish a comparison model， Through the comparisonanalysis of the disadvantages of the two models and feasibility, provide reference for the research behind.