班主任应具备的基本素质和工作方法

班主任工作的好坏,直接影响着学校整体学生管理工作。提高班主任素质,不断探索班主任工作的新途径、新方法,才能实现班主任工作的新突破,开创班主任工作的新局面。     

等、变深度舰船水压场的理论计算

在浅水、薄船、无限宽水域的条件下,舰船以亚临界速度(F_H<1)运动时,利用E.O.Tuck提出的渐近匹配展开法,可以得到定深度扰动速度势的摄动方程。对水深缓慢变化的海底,舰船的绕流不再是定常的,根据A.Plotkin所采用的多重尺度法,可以得到变深度浅水舰船扰动速度势的摄动方程。如果仅考虑扰动速度势的一阶摄动方程,则可得到考虑了线性兴波影响的舰船水压场的计算公式。     

高速水射流倒空弹体装药安全性研究

本文阐述了高速水射流倒空弹体装药的机理,建立了确定水射流引爆炸药的临界速度的模拟实验方法和模型,进行了高速水射流冲击炸药的安全性试验,并对试验结果进行了分析,证明在工作泵压下高速水射流倒空弹体装药安全、可靠。     

利用火箭深弹系统拦截鱼雷的技术改进方法探析

多功能、多用途是火箭深弹系统的主要发展方向之一。根据水面舰艇武器装备的实际,仅从拦截潜艇发射的鱼雷角度出发,对舰载火箭深弹系统拦截来袭鱼雷的可行性进行了分析。在此基础上,探讨了利用火箭深弹系统拦截鱼雷的系统选择、深弹战斗部的开发、引信选型、发射管安装及配置、火控系统的改进等关键问题,并提出了一些具体的改进方法。     

悬浮式深弹反鱼雷武器系统的有效拦截域分析

针对悬浮式深弹反鱼雷武器系统在作战使用中需对目标的可拦性进行快速判断的需求,提出了系统有效拦截域的概念,又根据系统作战流程和工作原理,将有效拦截域判断条件细化为时间域和空间域两个方面判据,进而构建了基于实战中可获取的战场态势等相关信息计算系统有效拦截域的数学模型,并具体给出了一个计算实例。研究结果可为其作战使用提供一定参考。     

基于垂直线列阵的深海被动目标定深误差

首先研究了在深海环境下,采用三阵元垂直线列阵水声探测系统进行被动目标定深的基本原理。然后分别从随机误差、阵元配置偏差和相干多途水声信道干扰的角度,对被动目标定深的误差源进行了理论分析,并推导了相关公式。通过仿真实验,总结出各误差源对被动目标定深精度影响的规律,为进一步开展被动目标定深研究、提高被动目标定深精度奠定了基础。     

Effect of wave shaper on reactive materials jet formation and its penetration performance

Wave shaper effect on formation behavior and penetration performance of reactive liner shaped charge (RLSC) are investigated by experiments and simulations. The reactive materials liner with a density of 2.3 g/cm³ is fabricated by cold pressing at a pressure of 300 MPa and sintering at a temperature of 380 °C. Experiments of the RLSC with and without wave shaper against steel plates are carried out at standoffs of 0.5, 1.0, and 1.5 CD (charge diameter), respectively. The experimental results show that the penetration depths and structural damage effects of steel plates decrease with increasing the standoff, while the penetration depths and the damage effects of RLSC without wave shaper are much greater than that with wave shaper at the same standoff. To understand the unusual experimental results, numerical simulations based on AUTODYN-2D code are conducted to discuss the wave shaper effect, including the propagation behavior of detonation wave, the velocity and temperature distribution of reactive jet, and penetration depth of reactive jet. The simulations indicate that, compared with RLSC without wave shaper, there is a higher temperature produced inside reactive jet with wave shaper. This unusual temperature rise effects are likely to be an important mechanism to cause the initiation delay time of reactive jet to decline, which results in significantly decreasing its penetration performance.     

Theoretical and numerical simulation study on jet formation and penetration of different liner structures driven by electromagnetic pressure

The use of a shaped liner driven by electromagnetic force is a new means of forming jets. To study the mechanism of jet formation driven by electromagnetic force, we considered the current skin effect and the characteristics of electromagnetic loading and established a coupling model of"Electric—Magnetic—Force"and the theoretical model of jet formation under electromagnetic force. The jet formation and penetration of conical and trumpet liners have been calculated. Then, a numerical simulation of liner collapse under electromagnetic force, jet generation, and the stretching motion were performed using an ANSYS multiphysics processor. The calculated jet velocity, jet shape, and depth of penetration were consistent with the experimental results, with a relative error of less than 10％. In addition, we calculated the jet formation of different curvature trumpet liners driven by the same loading condition and ob-tained the influence rule of the curvature of the liner on jet formation. Results show that the theoretical model and the ANSYS multiphysics numerical method can effectively calculate the jet formation of liners driven by electromagnetic force, and in a certain range, the greater the curvature of the liner is, the greater the jet velocity is.     

Investigate the effects of magnetic fields on the penetration ability of a shaped charge jet at different standoffs

The influence of a magnetic field on the stability of a shaped charge jet is experimentally investigated at standoffs of 490, 650 and 800 mm. The experimental results without and with the magnetic field are compared in terms of the shaped charge jet form, stability and penetration ability. A theoretical model based on one-dimension fluid dynamics is then developed to assess the depth of penetration of the shaped charge at those three standoffs and magnetic conditions. The results show that the penetration capability can be enhanced in more than 70% by the magnetic field. The theoretical calculations are compared with the experimental results with reasonably good correlation. In addition, the parameters introduced in the theory are discussed together with the experiments at three standoffs studied.     

聚能射流形成过程的理论建模与分析

分析了聚能射流的形成过程,并对其中的各阶段进行了详细建模。在模型中考虑了炸药爆轰、金属的驱动、药型罩压垮以及射流和杵体的形成过程。采用该模型对某一聚能装药结构进行了计算,计算结果表明:药型罩顶部和底部微元的压垮速度较小,在射流头部形成反向速度梯度,与试验数据吻合较好。该模型对于多级侵彻战斗部的工程设计与侵彻参数的计算具有一定的参考价值。