水气双重介质共同作用下滑行艇纵向运动预报

为探究滑行艇水气双重介质共同作用下的运动响应情况,针对喷水推进滑行艇的高速运动原理,建立水气双重介质作用下滑行艇非线性的纵向运动数学模型。分析滑行艇在水气双重介质共同作用下滑行过程中的受力特性,确定艇体受到的重力、浮力、动升力和风压阻力等,改进受风面积和风压力臂的计算方法,提出实时计算滑行艇浸湿长度的计算公式。编写滑行艇纵向运动预报程序,并对不同工况下滑行艇运动的预报结果予以了分析。结果显示,当主机输出功率一定时,计入空气比不计入空气时的航速下降5.1%,升沉量下降0.006 m,纵摇角抬升0.2°,阻力增加1 893 N,动升力减小404 N;而计入风的阻力对滑行艇的运动影响较大,航速下降15.3%,纵摇角增加0.6°,升沉量下降0.021 m,动升力下降1 139 N,阻力增加5 472 N。

Longitudinal Motion Prediction of Planning Craft in Water-Air Dual Porous Media

In order to probe motion response of high-speed planning craft in water-air dual porous media,this paper established a mathematical model for the non-linear longitudinal motion according to high-speed sliding theory of water-jet propelled planning crafts.Firstly,the forces on sliding planning craft hull in water-air dual porous media were analyzed,and gravitation,buoyancy,hydrodynamic lift and pressure resistance were presented.Secondly,the calculation method of windward area and wing pressure level were improved,and the calculation formula of the wetted length was proposed.Finally,the paper worked on a longitudinal motion prediction program for planning craft,and finished the result analysis of planning crafts motion prediction in different conditions.The results show that,when the output power of main engine is constant,considering air versus not considering air makes the ship speed decrease 5.1%,the heave decrease 0.006 m,the pitch angle increase 0.2°,resistance increase 1 893 N,the hydrodynamic lift decrease 404 N.Meanwhile,considering wind resistance has a great influence on motion of the planning craft： the ship speed decreases 15.3%,the heave decreases 0.021 m,the pitch angle increases 0.6°,resistance increases 5 472 N.