虾蟹塘投饵船三叶螺旋桨设计及水动力仿真分析

Hydrodynamic simulation analysis of three-blade propeller of shrimp and crab pond feeding boat

摘要:

为提高虾蟹塘投饵船投饵精确率，降低工作能耗，增加工作稳定性及可靠性，提出一种针对虾蟹塘投饵船的三叶螺旋桨设计方法。根据船体尺寸和整体功耗上限确定3种适宜虾蟹塘投饵船搭载的螺旋桨，直径尺寸分别为0.05、0.06和0.07 m，并以船舶螺旋桨射流理论方程和叶片边缘点坐标方程为基础，通过叶片边缘三维坐标生成三维叶片曲线，从而建立螺旋桨三维模型。应用Ansys CFD软件，采用雷诺平均纳维叶-斯托克斯（RANS）方程以及SST k-ω湍流模型构建水动力仿真实验，分析螺旋桨最大轴向射流速度与平均轴向射流速度之间的误差，通过分析各螺旋桨叶片截面压力、转速以及平均轴向射流速度之间的关系来获得具有较好敞水性能的螺旋桨。通过虾蟹塘实地试验，分析实际船速与最大轴向射流速度之间的误差，验证螺旋桨设计的可靠性，同时在满足虾蟹塘投饵船船速、船体推力以及整体功耗的情况下，以螺旋桨工作效率为试验指标，对比在不同转速下各直径螺旋桨的实际工作效率。结果表明：针对虾蟹塘投饵船螺旋桨的设计方法是可行的，实际船速与最大轴向射流速度之间的误差小于10%，同时，虾蟹塘投饵船在搭载直径0.07 m螺旋桨、转速3 500 r/min时，螺旋桨工作能耗为135 W，最高平均船速为1.46 m/s，工作效率达70.9%。

Abstract:

In order to improve the accuracy of feeding boats in shrimp and crab ponds, reduce energy consumption, and increase stability and reliability, a design and hydrodynamic simulation experiment is proposed for the three-blade propeller of feeding boats in shrimp and crab ponds. According to the hull size and the upper limit of overall power consumption, the propeller diameters of the three suitable shrimp and crab pond feeding boats were set to be 0.05, 0.06 and 0.07 m, respectively, and the theoretical equation of the ship's propeller jet and the coordinate equation of the blade edge point are as follows:Basically, a three-dimensional blade curve is generated from the three-dimensional coordinates of the blade edge to establish a three-dimensional model of the propeller. Using Ansys CFD software, the Reynolds average Navier-Stokes (RANS) equation and the SST k-ω turbulence model were used to construct a hydrodynamic simulation experiment, and the error between the maximum axial jet velocity and the average axial jet velocity of the propeller was analyzed. The relationship between blade section pressure, rotation speed and average axial jet velocity was analysed to obtain the propeller with the best open water performance. Through the shrimp and crab pond field experiments, the error between the actual ship speed and the maximum axial jet velocity was analyzed to verify the reliability of the propeller design. At the same time, it met the requirements of the shrimp and crab pond feeding boat speed, hull thrust and overall power consumption. Taking the working efficiency of the propeller as the experimental index, the actual working efficiency of the propellers of different diameters at different speeds was compared. The results show that the design method for the propeller of the shrimp and crab pond feeding boat is feasible. The error between the actual ship speed and the maximum axial jet velocity is less than 10%. At the same time, the shrimp and crab pond feeding boat is equipped with a 0.07 m diameter propeller. When the rotating speed is 3 500 r/min, the working energy consumption of the propeller is 135 W, the highest average ship speed is 1.46 m/s, and the working efficiency reaches 70.9%.