The speed of a ship sailing in waves always slows down due to the decrease in efficiency of the propeller. So it is necessary and essential to analyze the unsteady hydrodynamic performance of propeller in waves. This ...The speed of a ship sailing in waves always slows down due to the decrease in efficiency of the propeller. So it is necessary and essential to analyze the unsteady hydrodynamic performance of propeller in waves. This paper is based on the numerical simulation and experimental research of hydrodynamics performance when the propeller is under wave conditions. Open-water propeller performance in calm water is calculated by commercial codes and the results are compared to experimental values to evaluate the accuracy of the numerical simulation method. The first-order Volume of Fluid(VOF) wave method in STAR CCM+ is utilized to simulate the three-dimensional numerical wave. According to the above prerequisite, the numerical calculation of hydrodynamic performance of the propeller under wave conditions is conducted, and the results reveal that both thrust and torque of the propeller under wave conditions reveal intense unsteady behavior. With the periodic variation of waves, ventilation, and even an effluent phenomenon appears on the propeller. Calculation results indicate, when ventilation or effluent appears, the numerical calculation model can capture the dynamic characteristics of the propeller accurately, thus providing a significant theory foundation forfurther studying the hydrodynamic performance of a propeller in waves.展开更多
In this paper, wave-body interactions under the effects of complex topography are investigated numerically by a two-phase incompressible Reynolds-Averaged Navier-Stokes(RANS) solver in OpenFOAM. A submerged bottom-sta...In this paper, wave-body interactions under the effects of complex topography are investigated numerically by a two-phase incompressible Reynolds-Averaged Navier-Stokes(RANS) solver in OpenFOAM. A submerged bottom-standing structure is distributed below the floating body, and the effects of the water depth and top width of the submerged structure on wave-body interactions are studied. The results show that the submerged structure can affect wave loads and roll motion. The vertical force can be amplified on the fixed body when the water depth of the submerged structure is smaller than half of the water depth of the body. The top width significantly affects the vertical force when the top width is smaller than the incident wave length and larger than the body width. For the free-rolling body, roll amplitude can be increased when the ratio of the incident wave length to the water depth of the submerged structure is large enough. On the resonance condition, roll amplitude is slightly reduced by the submerged structure. The effects of the top width on roll amplitude are remarkable when special conditions are fulfilled.展开更多
基金Supported by the National Natural Science Foundation of China （51379043, 41176074, 51209048, 51409063）, High Tech Ship Research Project of Ministry of Industry and Technology （G014613002）, and the Support Plan for Youth Backbone Teachers of Harbin Engineering University （HEUCFQ 1408）
文摘The speed of a ship sailing in waves always slows down due to the decrease in efficiency of the propeller. So it is necessary and essential to analyze the unsteady hydrodynamic performance of propeller in waves. This paper is based on the numerical simulation and experimental research of hydrodynamics performance when the propeller is under wave conditions. Open-water propeller performance in calm water is calculated by commercial codes and the results are compared to experimental values to evaluate the accuracy of the numerical simulation method. The first-order Volume of Fluid(VOF) wave method in STAR CCM+ is utilized to simulate the three-dimensional numerical wave. According to the above prerequisite, the numerical calculation of hydrodynamic performance of the propeller under wave conditions is conducted, and the results reveal that both thrust and torque of the propeller under wave conditions reveal intense unsteady behavior. With the periodic variation of waves, ventilation, and even an effluent phenomenon appears on the propeller. Calculation results indicate, when ventilation or effluent appears, the numerical calculation model can capture the dynamic characteristics of the propeller accurately, thus providing a significant theory foundation forfurther studying the hydrodynamic performance of a propeller in waves.
基金supported by the National Key Research and Development Program of China under Grand No.2016YFB0200902supported by the Program for Guangdong Introducing Innovative and Entrepreneurial Teams under Grant No.2016ZT06D211
文摘In this paper, wave-body interactions under the effects of complex topography are investigated numerically by a two-phase incompressible Reynolds-Averaged Navier-Stokes(RANS) solver in OpenFOAM. A submerged bottom-standing structure is distributed below the floating body, and the effects of the water depth and top width of the submerged structure on wave-body interactions are studied. The results show that the submerged structure can affect wave loads and roll motion. The vertical force can be amplified on the fixed body when the water depth of the submerged structure is smaller than half of the water depth of the body. The top width significantly affects the vertical force when the top width is smaller than the incident wave length and larger than the body width. For the free-rolling body, roll amplitude can be increased when the ratio of the incident wave length to the water depth of the submerged structure is large enough. On the resonance condition, roll amplitude is slightly reduced by the submerged structure. The effects of the top width on roll amplitude are remarkable when special conditions are fulfilled.
