在进行变尺度船模系列试验、大尺度船模自航试验、几何相似船模尺度效应试验或者比较不同尺度水池的试验结果时,必然要遇到阻塞效应问题.在水池尺度较小、船模尺度相对较大时,阻塞效应尤其突出.阻塞效应混在各种分析结果中,影响结论的准确性,必须予以修正.采用计算流体力学(CFD)方法,通过改交计算域的大小来改变阻塞比,利用流体体积分数(VOF)方法捕捉船舶的自由液面,计及升沉和纵倾两个自由度,对两种船型进行了不同阻塞比、不同航速下的阻力数值计算,探究船型、水池宽度和深度与阻塞效应影响程度的关系,获得了阻塞效应的影响规律,并对拖曳水池的阻塞效应修正提出了合理化建议.
In variable metric series model test, large scale model self-propulsion test, geometric similarity model scale effect test or comparing the test results of different scale towing tank, the blockage effect will be inevitably encountered. When the towing tank scale is small, and the ship model scale is relatively large, the blockage effect is especially prominent. The blockage effect must be corrected, or it will mix among all kinds of analytical results and affect the accuracy of the conclusion. The method of computational fluid dynamics (CFD) is adopted and numerical calculation of the ship resistance for two types of ships under different blockage ratios and speeds is carried out to study the influence of ship form, width and depth of tank on ship resistance. The blockage ratio is changed by changing the size of the computational domain, and the volume of fluid (VOF) method is used to capture the fluid free surface of the ship. In the numerical study, the heaving and pitching motions are considered. Finally, the influence regularity of the blockage effect is obtained, and the reasonable suggestions are put forward for the correction of the blockage effect of the towing tank.