Numerical study of influence of blockage effect of towing tank on different ship types

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.