船舶推进中两种动态平衡的研究

Research on two dynamic blance in the ship's propulsion process

为了明确船舶推进中功率、力等各物理量之间的平衡关系,正确使用船舶主机防止其超负荷提供相应的理论依据,文章分析了螺旋桨的推力与船舶航行阻力的动态平衡过程。推导了螺旋桨转速、船舶的航速、螺旋桨的相对进程以及螺旋桨所消耗的功率等各物理量之间的关系,即:当螺旋桨的相对进程一定时,船舶的航速与螺旋桨的转速成正比,螺旋桨消耗的功率与其转速的三次方成正比;而当螺旋桨的转速一定时,随船舶航行阻力系数的增大,船舶的航速将减小,螺旋桨消耗的功率将增大。最后,在上述理论分析的基础上,进一步讨论了螺旋桨的转速发生变化时,船舶的航行经济性问题。

In order to clarifying the relationship among such physical quantities as power and force in the ship＇s propulsion process and supplying theoretic reference for using the ship＇s main engine promptly without overloading,the dynamic blance between the propeller＇s thrusting force and the ship＇s sailing resitance are analyzed.Also the relationship of the propeller＇s speed,the ship＇s velocity,the propeller＇s relative advance coefficient and the propeller＇s consuming power are deduced,that is,when the the propeller＇s relative advance coefficient is constant,the ship＇s velocity is proportion to the propeller＇s speed and the the propeller＇s consuming power is proportion to the cube of the propeller＇s speed.However,when the propeller＇s speed is constant,with the increase of the sailing resistant coefficient,the ship＇s velocity will decrease and the propeller＇s consuming power will increase.Base on the analysis above,there is a discussion on the ship＇s economy in sailing process.