喷水推进高速三体滑行艇数值自航研究  

Numerical simulation for self-propulsion study of a high-speed planning trimaran

作　　者：仝博[1] 王永生[1] 杨琼方[1] 刘承江[1] TONG Bo;WANG Yong-sheng;YANG Qiong-fang;LIU Cheng-jiang(College of Power Engineering,Naval University of Engineering,Wuhan 430033,China)

机构地区：[1]海军工程大学动力工程学院,武汉430033

出　　处：《船舶力学》2018年第7期789-796,共8页Journal of Ship Mechanics

基　　金：高性能喷泵与进水流道的最优化设计及其与船体的匹配研究(51309229);船体与喷水推进器相互作用机理及其尺度效应研究(51209212)

摘　　要：为了验证计算流体力学(CFD)方法预报滑行艇自由液面粘性流场的精确度,判断为某三体滑行艇设计的喷水推进器能否满足快速性要求,采用CFD方法对某喷水推进高速(1<Fr_L<1.8)三体滑行艇进行两相流的数值自航,并与试验值比较。运用切割体网格技术并基于RANS VOF求解,首先计算了五个不同速度下的裸艇阻力。结果表明:阻力系数最大误差8.3%,最小误差0.5%,达到了较好的计算精度;采用等推力系数法,在模型尺度下进行"滑行艇+喷泵"的数值自航,将结果推算到实尺度艇,结果表明该喷泵可以达到设计航速;高速航行时推力减额为负的主要原因是艇首尾压差阻力的显著降低。计算结果显示,考虑自由液面时滑行艇底部会出现不合理的水气分布,这影响到滑行艇的阻力性能和喷泵的推进性能,通过局部网格加密可以显著减少艇底非正常水气分布,但艇底气水层难以完全消除,这可能是CFD方法预报滑行艇阻力精度难以控制的原因之一。In order to validate the precision of CFD method on predicting resistance performance and vi鄄cious free surface flow of the planning hull,and to judge whether the waterjet designed for a trimaran-plan鄄ing hull can meet the demand of rapidity,Computational Fluid Dynamics(CFD)method was applied to pre鄄dict the resistance and self-propulsion performance of a high speed(1约FrL约1.8)planing trimaran with free surface.Based on RANS VOF solver and trimmed mesh techniques,the resistance of bare craft was calcu鄄lated in five conditions of different speeds,the results that the maximum error was 8.3%and the minimum er鄄ror was 0.5%agreed well with the model tests.Identical thrust coefficient method was applied to predict the self-propulsion performance of the planing trimaran on model scale,and the results were extrapolated to full scale craft,which shows that the designed waterjet propulsor could overcome the resistance of the full scale craft and reach the design speed.Thrust reduction being negative was due to the remarkable reduction of the pressure between the bow with the stern.The irrational VOF distributions occurred on the bottom of the hull when the free surface was considered,which can influence the resistance and propulsive performance of the planing hull.The air film on the bottom can be decreased obviously by local refining mesh,but it can not be eliminated absolutely,which may be one of the reasons of difficulty to control the computational ac鄄curacy of the planing hull爷s resistance.

关 键 词：高速三体滑行艇 计算流体力学 阻力 自航 推力减额 水气分布 

分 类 号：U664.34[交通运输工程—船舶及航道工程]