基于CFD的船式拖拉机兴波阻力研究

Research on wave-making resistance of ship tractor based on CFD

船式拖拉机作业过程中容易形成兴波,其严重影响种苗的播种质量。为降低船式拖拉机在水田行走过程中的兴波,通过旋转流变仪试验测定泥浆参数,基于CFD算法建立VOF空气和泥浆双相流的船体滑行模型,研究船式拖拉机的前进速度、船体长宽比对船体兴波阻力、兴波高度及兴波作用区域的影响。结果表明,兴波阻力、兴波高度和兴波作用区域随速度增大而增大;当前进速度为2 m/s时凹船壳相对于平船壳船首和船尾兴波高度分别降低0.052 m和0.028 m;船行波衰减率为3.7%,当船体长宽比为19时船体所受兴波阻力最小的结论。

During the operation of ship tractor, it is easy to form wave, which seriously affects the sowing quality of seedlings. To reduce ship type wave, in the process of walking tractors in the paddy field by mud rotary rheometer test parameters, based on CFD algorithms VOF air and mud planning hull model of two-phase flow, the ship of the tractor forward speed, hull length-width ratio on hull the wave-making resistance, the influence of wave height and wave action area. The results show that the wave resistance, wave height and wave acting area increase with the increase of velocity. When the current advancing speed is 2 m/s, the wave height of concave hull decreases by 0.052 m and 0.028 m, respectively, relative to the bow and stern of flat hull. The conclusion that the attenuation rate of traveling wave is 3.7% and the wave resistance is the least when the aspect ratio is 19.