气垫船艏部围裙-跳板下放过程仿真方法及耦合响应特性研究

Simulation Method and Coupled Response of Bow Skirt-Ramp Deployment in Hovercraft

  • 摘要: 【目的】针对气垫船登陆过程中艏部登陆跳板在排气受限等工况下下放效率与稳定性不足的问题,研究气囊—跳板耦合系统的动力学响应特性,探索异常工况下提升跳板可靠下放能力的有效方法。【方法】基于显式动力学有限元方法,建立气垫船艏部围裙气囊—登陆跳板刚-柔-气耦合数值模型,系统分析不同排气孔面积参数条件下跳板下落过程中气囊内压、排气质量流量以及跳板运动响应特性;针对排气失效工况,通过引入等效机械传动装置,以模拟施加额外机械扭矩来主动驱使跳板下放。【结果】在正常排气条件下,排气孔面积是控制气囊卸压过程及登陆跳板下放动力学行为的主导参数。当单个排气孔面积由0.1 m²增大至0.45 m²时,气囊内压衰减速率显著提高,跳板进入重力主导下落阶段的时间明显提前,下放时间由11.3 s缩短至2.6 s,角速度峰值整体呈上升趋势且响应表现出非单调变化特征。拟合分析表明,排气孔面积与跳板下放时间呈稳定反相关关系;相比之下,跳板质量由6256 kg增加至8181 kg时,下放时间仅缩短约0.5 s,表明其对系统响应影响有限,表现出明显的边际效应。在排气失效工况下,引入等效机械传动装置施加附加转矩可有效缩短跳板下落时间并提升运动稳定性;当固定角速度由0.14 rad/s增大至0.22 rad/s时,维持匀速下落所需最大额外机械力矩由1.16×10E6 N·m增大至1.54×10E6 N·m,且随下落历程呈阶段性增大趋势,并与角速度呈正相关关系。气囊应力分析表明,前端褶皱区及侧向鼓起区域为主要受力与变形集中部位。【结论】通过合理匹配气囊排气孔与跳板结构参数,并在异常工况下辅以机械传动装置,可有效提升气垫船登陆跳板下放的可靠性与作业效率。

     

    Abstract: Objectives To address the insufficient deployment efficiency and stability of bow landing ramps in hovercraft during landing operations under conditions such as restricted air exhaust, the dynamic response characteristics of the airbag–ramp coupled system are investigated, and effective approaches to enhance the reliable deployment capability of the ramp under abnormal conditions are explored. Methods Based on an explicit dynamic finite element approach, a rigid–flexible–fluid coupled numerical model of the bow skirt airbag–landing ramp system is established. The effects of different orifice area parameters on airbag internal pressure, exhaust mass flow rate, and ramp motion response during the ramp lowering process are systematically analyzed. For exhaust failure conditions, an equivalent mechanical transmission device is introduced to simulate the application of additional mechanical torque for actively driving ramp deployment. Results The results indicate that under normal exhaust conditions, the orifice area is the dominant parameter governing the airbag depressurization process and the dynamic behavior of ramp deployment. When the single orifice area increases from 0.1 m² to 0.45 m², the internal pressure decay rate is significantly accelerated, the transition to gravity-dominated motion occurs earlier, and the deployment time is reduced from 11.3 s to 2.6 s. Meanwhile, the peak angular velocity generally increases and exhibits a non-monotonic response characteristic. Fitting analysis further reveals a stable inverse correlation between the orifice area and ramp deployment time. In contrast, increasing the ramp mass from 6256 kg to 8181 kg shortens the deployment time by only about 0.5 s, indicating a limited influence on system response and a clear marginal effect. Under exhaust failure conditions, the introduction of an equivalent mechanical transmission device with controlled additional torque effectively shortens the deployment time and enhances motion stability. When the prescribed angular velocity increases from 0.14 rad/s to 0.22 rad/s, the maximum additional mechanical torque required to maintain uniform deployment increases from 1.16×10E6 N·m to 1.54×10E6·N·m, showing a stage-wise increasing trend during deployment and a positive correlation with angular velocity. Furthermore, stress analysis identifies the front folding region and lateral bulging region of the airbag as the primary zones of stress and deformation concentration. Conclusions By appropriately matching the airbag orifice parameters and ramp structural parameters, and employing mechanical transmission assistance under abnormal conditions, the reliability and operational efficiency of hovercraft landing ramp deployment can be effectively improved.

     

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