Numerical prediction method of shafting power characteristics of free self-propelled ship in waves
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摘要:
目的 为了研究船舶在波浪中约束模与自航模运动特性的差异以及船舶轴系功率特性,开展船舶波浪中自航性能数值仿真预报。 方法 首先,选取KCS船模和KP505桨模,采用URANS方法进行船舶波浪自由直航CFD模拟;然后,基于自研URANS求解器HUST-Ship与自研结构化动态重叠网格代码HUST-Overset,以及改进型体积力螺旋桨推进模型,对船舶在不同波浪条件下的运动响应进行耦合求解,包括两自由度KCS约束模运动仿真和三自由度自航模自由直航仿真,并对比这2种方法预报船舶运动特性的差异;最后,采用对数分析法得出波浪中船舶自由直航功率增加的主要成分及其具体占比。 结果 KCS船模在波浪中自航时,推进效率和波浪增阻对功率增加的贡献占比分别为23%~26%和74%~77%,即波浪增阻占比较大。 结论 因此,降低波浪中功率增加的最有效方法是减小船舶运动以降低波浪增阻。 Abstract:Objective To investigate ship power characteristics and the difference between the towing model and self-propulsion model for ship motion response in waves, numerical simulations of ship self-propulsion performance in waves are carried out. Methods In this paper, the KCS ship model and KP505 propeller model are selected, and the unsteady Reynolds-averaged Navier-Stokes (URANS) method is used to carry out computational fluid dynamics (CFD) simulations of ship self-propulsion in waves. The in-house URANS solver HUST-Ship and in-house structured dynamic overset grid code HUST-Overset are combined to solve the motions of the self-propelled ship in waves, and the improved body-force model is selected as the propulsion model. Towing simulations for KCS with two-degrees-of-freedom (DOF) in waves and self-propulsion simulations with 3-DOFs under different wave conditions are carried out, and the differences between these methods are discussed in detail. Finally, the components and their specific proportions of added power during ship self-propulsion in waves are analyzed in detail using the logarithmic analysis method. Results Regarding the added power of a self-propelled KCS in waves, the added resistance is responsible for 74%-77% while propulsive efficiency accounts for 23%-26%, that is, the added resistance occupy a larger proportion. Conclusion Reducing ship motion to decrease added resistance is the most effective approach to reducing added power. -
表 1 CFD仿真工况的参数设置
Table 1. Parameter setting of CFD simulation cases
仿真工况编号 波长λ/Lpp 波高A/Lpp 推进模型 1 静水 静水 w/o 2 0.65 0.0108 3 0.85 0.0142 4 1.15 0.0192 5 1.95 0.0325 6 0.65 0.0108 MOUM 7 0.85 0.0142 8 1.15 0.0192 9 1.95 0.0325 表 2 不同网格和时间步长下的不确定度分析结果
Table 2. Uncertainty analysis results under different grids and time steps
rG 结果 (UG / D) /% rT 结果 (UT / D) /% SG1 SG2 SG3 ST1 ST2 ST3 CT $ \sqrt 2$ 10.542 11.811 11.999 4.04 2 10.552 11.811 11.914 0.29 TF3 0.922 0.935 0.938 1.12 0.920 0.935 0.942 1.42 TF5 1.136 1.111 1.107 0.95 1.131 1.111 1.103 1.20 表 3 基于试验数据的验证结果
Table 3. Validation results based on test data
(UG / D) /% (UT / D) /% (USN / D) /% (UD / D) /% (UV / D) /% (E / D) /% CT 4.04 0.29 4.33 8 9.10 8.94 TF3 1.12 1.42 2.54 4 4.74 0.37 TF5 0.95 1.20 2.15 4 4.54 0.65 表 4 波浪增阻与波浪中自航的仿真结果
Table 4. Simulation results of added resistance and self-propulsion in waves
λ/Lpp ΔR/N Q/(N·m) n/(r·s−1) 静水 0 2.049 12.021 0.651 2.129 2.325 12.754 0.851 10.8 2.41 13.092 1.15 45.556 3.474 15.227 1.951 15.905 2.555 13.475 -
[1] ZHANG L, ZHANG J N, SHANG Y C. A practical direct URANS CFD approach for the speed loss and propulsion performance evaluation in short-crested irregular head waves[J]. Ocean Engineering, 2021, 219: 108287. doi: 10.1016/j.oceaneng.2020.108287 [2] SIMONSEN C D, OTZEN J F, JONCQUEZ S, et al. EFD and CFD for KCS heaving and pitching in regular head waves[J]. Journal of Marine Science and Technology, 2013, 18(4): 435–459. doi: 10.1007/s00773-013-0219-0 [3] 魏成柱, 易宏, 李英辉. 新概念高速穿梭艇系列船型及其直航性能[J]. 中国舰船研究, 2017, 12(2): 12–21. doi: 10.3969/j.issn.1673-3185.2017.02.002WEI C Z, YI H, LI Y H. Hull forms and straight forward CFD free running trials of high-speed shuttle vessels[J]. Chinese Journal of Ship Research, 2017, 12(2): 12–21 (in Chinese). doi: 10.3969/j.issn.1673-3185.2017.02.002 [4] 张明霞, 卢鹏程, 王志豪. 小水线面三体船耐波性数值模拟[J]. 中国舰船研究, 2020, 15(4): 135–143,152.ZHANG M X, LU P C, WANG Z H. Numerical simulation of seakeeping performance of a trimaran small waterplane area center hull[J]. Chinese Journal of Ship Research, 2020, 15(4): 135–143,152 (in Chinese). [5] JIN Y T, CHAI S H, DUFFY J, et al. URANS predictions of wave induced loads and motions on ships in regular head and oblique waves at zero forward speed[J]. Journal of Fluids and Structures, 2017, 74: 178–204. doi: 10.1016/j.jfluidstructs.2017.07.009 [6] 王建华, 万德成. 自航船舶在首斜浪中航向保持的数值模拟[J]. 水动力学研究与进展(A辑), 2018, 33(6): 740–748.WANG J H, WAN D C. Numerical investigations of free running ship in bow quartering waves under course keeping control[J]. Chinese Journal of Hydrodynamics, 2018, 33(6): 740–748 (in Chinese). [7] LEE C M, SEO J H, YU J W, et al. Comparative study of prediction methods of power increase and propulsive performances in regular head short waves of KVLCC2 using CFD[J]. International Journal of Naval Architecture and Ocean Engineering, 2019, 11(2): 883–898. doi: 10.1016/j.ijnaoe.2019.02.001 [8] FENG D K, YU J W, HE R, et al. Improved body force propulsion model for ship propeller simulation[J]. Applied Ocean Research, 2020, 104: 102328. doi: 10.1016/j.apor.2020.102328 [9] FENG D K, YU J W, HE R, et al. Free running computations of KCS with different propulsion models[J]. Ocean Engineering, 2020, 214: 107563. doi: 10.1016/j.oceaneng.2020.107563 [10] YU J W, YAO C B, LIU L W, et al. Assessment of full-scale KCS free running simulation with body-force models[J]. Ocean Engineering, 2021, 237: 109570. doi: 10.1016/j.oceaneng.2021.109570 [11] ZHANG Z G, GUO L X, WEI P, et al. Numerical simulation of submarine surfacing motion in regular waves[J]. Iranian Journal of Science and Technology, Transactions of Mechanical Engineering, 2020, 44(2): 359–372. doi: 10.1007/s40997-018-0259-5 [12] LIU L W, CHEN M X, YU J W, et al. Full-scale simulation of self-propulsion for a free-running submarine[J]. Physics of Fluids, 2021, 33(4): 047103. doi: 10.1063/5.0041334 [13] MENTER F R. Two-equation eddy-viscosity turbulence models for engineering applications[J]. AIAA Journal, 1994, 32(8): 1598–1605. doi: 10.2514/3.12149 [14] BURG C O E. Single-phase level set simulations for unstructured incompressible flows[C]//17th AIAA Computational Fluid Dynamics Conference. Toronto, Canada: American Institute of Aeronautics and Astronautics Inc., 2005. [15] 冯大奎, 鲁晶晶, 魏鹏, 等. 基于Level-set方法的三维数值水池造波研究[J]. 水动力学研究与进展(A辑), 2018, 33(4): 435–444.FENG D K, LU J J, WEI P, et al. The research of wave-generating in 3-D numerical wave tank based on level-set method[J]. Chinese Journal of Hydrodynamics, 2018, 33(4): 435–444 (in Chinese). [16] CARRICA P M, CASTRO A M, STERN F. Self-propulsion computations using a speed controller and a discretized propeller with dynamic overset grids[J]. Journal of Marine Science and Technology, 2010, 15(4): 316–330. doi: 10.1007/s00773-010-0098-6 [17] Tokyo 2015. A workshop on CFD in ship hydrodynamics[DB/OL]. (2015-12-2)[ 2021-12-30]. https://t2015.nmri.go.jp/index.html. [18] 李亭鹤, 阎超. 二维DRAGON网格自动生成技术的研究[J]. 空气动力学学报, 2005, 23(1): 88–92. doi: 10.3969/j.issn.0258-1825.2005.01.017LI T H, YAN C. Investigation of automatic generation technique for two-dimensional DRAGON grid[J]. Acta Aerodynamica Sinica, 2005, 23(1): 88–92 (in Chinese). doi: 10.3969/j.issn.0258-1825.2005.01.017 [19] 李亭鹤. 重叠网格自动生成方法研究[D]. 北京: 北京航空航天大学, 2004.LI T H. Investigation of chimera grid automatic generation algorithm[D]. Beijing: Beihang University, 2004 (in Chinese). [20] SANADA Y, KIM D H, SADAT-HOSSEINI H, et al. Assessment of experimental and CFD capability for KCS added power in head and oblique waves[C]//33rd Symposium on Naval Hydrodynamics. Osaka, Japan: [s. n. ], 2020. -
ZG2733_en.pdf
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