水下夯锤绕流阻力系数变化规律的数值模拟

Numerical simulation of change in flow resistance coefficient of underwater hammer

基于LS-DYNA流固耦合数值模拟方法,针对多个工程常用锤型进行数值模拟对比,分析了水下夯锤绕流阻力系数变化规律。结果表明:夯锤底面静压强一定时,夯锤质量越大,其绕流阻力系数越小;夯锤在水中下落的过程中,速度随着落距的增加而增大,但增长的幅度逐渐减小并趋于稳定;夯锤的能量利用率随着落距的增加而减小,其中夯锤底面静压强一定时,夯锤质量越小能量耗散率越大。

Change in the flow resistance coefficient of underwater hammers was analyzed through comparison of common types of hammers in multiple projects based on the LS-DYNA fluid-structure coupling numerical simulation method. The results show that,when the hydrostatic pressure on the bottom surface of the hammer is a fixed value,the flow resistance coefficient decreases with the increase of the hammer mass. The hammer fall velocity in the water increases with the drop distance,but the growth rate gradually decreases and tends toward a stable value. The energy usage ratio of the hammer decreases with the increase of the drop distance. When the hydrostatic pressure on the bottom surface is a fixed value,the energy dissipation rate increases with the decrease of the hammer mass.