Experimental Study And Analysis Of Hydroelasticity With Barge And KVLCC2

Recently,the global transportation ships are developing towards large-scale and highspeed.When analyzing the problem of seakeeping of very large ships,the traditional calculational method of rigid body assumption has been unable to accurately predict their real motion response.In this paper,the hydrodynamic response and hydroelastic response of ships in waves are studied systematically by both numerical simulation and physical model experiments.Based on the computational fluid dynamics software STAR-CCM+,a threedimensional viscous flow numerical wave tank was established in time domain.The numerical model adopts the combination of overset mesh,extruder mesh,trimmed mesh,DFBI model and other numerical technologies.A series of systematically and comprehensively convergence verifies were conduct from the aspects of time step,grid size,wave attenuation in space,width of calculation domain and length of damping zone.The numerical wave tank can generate the incident wave accurately and stably,and it can also solve the wave-body interaction problem efficiently and accurately.The hydroelastic response of Barge is studied by the method of sectional ship model experiments.The comprehensive analysis of multiple parameter changes is carried out from the aspects of same wave height,variable wave length and same wave length,variable wave steepness.At the same time,the motion response of rigid barges under the wave condition of multiple parameter changes is simulated.Under the rigid condition:when the wave height is constant,the response amplitude operators around the Barge tend to be consistent with the increase of the wave length;when the wave length is constant and the wave steepness is large,the nonlinear component of the wave increases,and the nonlinearity of the movement of the Barge also increases;under the condition of the large wave steepness,the strong nonlinear phenomena such as the head in and out water slamming will appear on the Barge,and the local strong wave system will be generated in the head and around the ship.When considering the elastic response,the dynamic response mode of elastic Barge near the head is quite different from the rigid numerical results.The response amplitude operators of elastic Barge are smaller than that of rigid Barge,and the change along the length direction is more gentle than that under rigid conditions.In this paper,the elastic response of KVLCC2 under the condition of multiple parameter variation is studied by the method of sectional ship model experiments.At the same time,the analysis of rigid KVLCC2 under the condition of multiple parameter variation is also carried out based on the numerical simulation,too.KVLCC2 elastic results show that when the incident wave length is less than once of the ship length and the incident wave amplitude is small,the hydroelastic response is small;when the incident wave length is between once of the length and 1.5 times of the ship length,whether the wave height change,or the wavelength change,the trends of response amplitude operator along the direction of the length are same,there is only slightly fluctuating in value.Under each rigid condition: when the incident wavelength is less than once of the ship length,the change of response amplitude operator of each monitoring point from bow to stern is very close to linearity;when the incident wavelength is greater than or equal to once of the ship length,the overall response amplitude operator of KVLCC2 increases with the wavelength;with the increase of wave length,the change of response amplitude operator in the direction of ship length tends to be gentle;for KVLCC2 there is no strong nonlinear phenomenon such as the bow in and out in the regular wave condition studied in this paper.The method of segmented ship model experiment can realize the hydroelastic effect of ship in waves.At the same time,based on the numerical simulation,the motion response analysis of rigid Barge and KVLCC2 under the incident wave with multiple parameter changes is carried out.The combination and comparison of the two methods can highlight the influence of hydroelastic response on the motion response of ship while studying the wave resistance response.