基于黏性等效的船舶顶浪运动降阶预报方法

Reduced-order prediction method of ship motion in head waves based on viscosity equivalence

针对势流预报方法速度快但精度受黏性影响显著、黏流预报方法精度高但计算效率较低的问题,提出一种基于黏性等效的耐波性预报降阶预报方法.该方法首先基于一种强迫放大运动,快速获取船舶阻尼随运动幅度变化的特性;再根据黏性等效原则和船舶运动状态,对无黏耐波性预报模型的阻尼进行实时修正.为验证该方法的有效性,以DTMB 5415船模为研究对象,开展了顶浪环境下的水池模型试验.结果表明:该方法预报的纵摇运动响应误差低于6.2%,垂荡运动响应误差低于15.6%;在仿真时间方面,该方法预报效率比传统黏流模型高出10倍以上.

To solve the issues that inviscid-flow model could simulate fast but inaccurate and viscous-flow model had high accuracy but low efficiency,the viscous equivalence reduced-order prediction method for seakeeping assessment was proposed.First,this method was based on a forced motion with amplified amplitude to quickly obtain the characteristics between ship damping and motion amplitude.Then,according to the principle of viscous equivalence and the motion state in real time,the corrected damping of inviscid-flow model was adjusted.To verify the effectiveness of this method,a towing tank experiment was conducted on the DTMB 5415 ship model in head waves.Results show that the pitch response error predicted by this method is less than 6.2%,and the heave response error is less than 15.6%.In terms of simulation time,the simulation efficiency of this method is more than 10 times higher than that of traditional viscous-flow model.