共查询到18条相似文献，搜索用时 296 毫秒
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采用LS-DYNA软件,对装药半径为0.15m、0.42m、0.55m的战斗部有、无壳体的爆炸特性进行数值模拟研究,分析了炸药在有无壳体的水下爆炸时的冲击波压力、气泡脉动压力等特性参数,对比总结了不同当量、不同装药半径及有无壳体的数值计算结果。结果表明:壳体对水下爆炸气泡脉动的影响是较为显著的。壳体厚度对气泡形成时间没有太多影响,但对气泡压力峰值影响较大。因此,研究战斗部水下爆炸威力时必须考虑壳体因素,不能简化。 相似文献
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基于战斗部水中爆炸威力评估方法,选取某型爆破型战斗部为研究对象,通过建立有效的爆破型战斗部有限元模型,设计出科学合理的仿真计算工况,利用 ALE 方法分析研究无限水域中壳体对爆破型战斗部爆炸威力的影响。 结果表明:壳体对爆炸威力的影响呈现出振荡衰减特性,且爆距越近振荡越大,爆距越远衰减越明显;壳体密度越大振荡越大,衰减越大。 可为水中兵器爆炸威力设计与评估提供参考。 相似文献
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预裂爆破具有形成光面、保护岩壁和减轻地震波等作用,用来建造码头还可以不必筑堰排水,爆破形成的岩壁可不加衬砌,直接供船舶停靠,因而具有很高的经济效益。本文叙述在坡度呈35～40°的致密角砾凝灰岩海岸上,建造一座岸壁码头的实例。码头具有结构简单,造价低和施工机具简单的优点。具有重力式所不可比拟的耐久性、承载力、抗震性、抗风浪、抗冲击,抗爆炸的能力。这对于建造外海和沿岸岛屿码头尤为重要。水下预裂爆破,同样适宜在江、河、湖、海建造水下洞库、岩基船坞、坞口导航墙,升船机的升船槽,船闸闸室等,具有广阔的发展前景。 相似文献
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超疏水表面在水下可以束缚气膜层，把部分固液接触界面转变为气液接触界面，并在气液界面上产生速度滑移以减小流动阻力，是一种新型高效减阻方法。从超疏水表面润湿特性出发，重点总结了超疏水表面水下减阻研究现状，分析了超疏水表面气液界面稳定维持的主要技术途径。最后，给出了提升气液界面稳定性的潜在突破方法，可为超疏水表面水下减阻技术的发展提供借鉴。 相似文献
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本文介绍的基岩水下爆破属临近重要建筑物的水下控制爆破。当岩石裂隙发育，且岩面有较厚的石碴覆盖层，其技术难度大，采取的诸如搭钢平台钻孔。塑料套管护孔，以及孔间、排间塑料导爆管雷管接力式微差起爆网路等措施，都是成功之经验，值得今后类似工程推广应用。 相似文献
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旨在研究声固耦合法模拟水下爆炸对圆筒的冲击,运用大型有限元软件 ABAQUS 声固耦合算法分别对密封圆筒与透水圆筒水下爆炸模型进行计算分析,并与理论公式结果进行对比分析。结果表明：利用 ABAQUS 声固耦合算法可以比较准确地模拟圆筒水下爆炸分析,能够满足工程要求;另外,在相同的水下爆炸作用下,透水圆筒比密封圆筒具有更好的抗爆炸和抗冲击性能。 相似文献
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介绍一种水下爆破切割装置的组成、特点、工作原理及试验情况,并对水压引信、水下聚能定向爆破等关键技术进行了有益的探讨。 相似文献
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岚山港通用泊位工程水下炸礁工程量为18×104m3,施工中采用了孔内毫秒微差爆破、孔间毫秒微差爆破、裸露爆破和导爆管起爆等先进技术。简述了施工参数计算、施工技术和安全措施。 相似文献
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青岛市中港东区码头工程水下爆岩工程量１．３万m^3,施工中采用了多段微差爆破,毫秒延迟爆破,导爆管起爆等多项为先进和成熟的施工技术,合理的施工组织,完善的施工管理,保证了工程质量,加快了工程进度。 相似文献
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水声信道中信号的时间相关特性是水声微弱信号相关检测的理论基础和具体参数选择依据。文中以厦门港典型的浅海声信道中信号的时间自相关和互相关特性进行实验研究。结果指出,信号有强的时间相关性,无论自相关或互相关性均比海洋环境噪声强得多,因此在水声信道中采用时间相关检测可望达到优良的抗噪声效果。 相似文献
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Evolution history and trend of the modern Huanghe River Delta 总被引：3，自引：1，他引：2
The evolvement history of modern Huanghe River Delta tidal flat, coastline and underwater terrain were studied based on the analysis of remote sensing images and water depth data. Based on the analysis of seafloor terrain evolution on different historical stages, a formula simulating the erosion and deposition evolvement model of subaqueous Huanghe River Delta slope was proposed, and the evolvement trend of the subaqueous delta terrain was predicted. The result shows that the equilibrium transition zone is near the water depth of 12 m with seabed erosion in shallower water and accumulation in deeper water during the first 150 a after the river channel was deserted. In the meantime, the underwater slope became gentler and the coastal erosion rate became slow gradually. Then, the subaqueous delta slope changed to up concave from upper convex, and the shape of subaqueous delta disappeared. The coast type changed to silt-mud coast about 100-150 a after the river course was deserted. The erosion depth in the foot of the seawall is calculated based on the formula. 相似文献
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The opportunities of diagnosing wind roughness with the help of underwater vision systems have been investigated. The model
of the rough sea surface image observed from under water under conditions of natural illumination has been developed. It has
been shown that the statistical processing of the image of a solar path which is formed as a result of light refraction at
randomly irregular air-water interface allows one to define not only the slope variance and the curvature variance of the
surface, but also the coefficient of spatial correlation of slopes. The algorithms for defining of characteristics of wind
roughness on the basis of images of underwater solar path and the results of their testing using the data of numerical and
natural experiments are given. It was found that waves of very small amplitude images with high contrast near borders of the
Snell’s circle (the underwater image of the sky). 相似文献
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从高压水射流技术在水下工程中应用及高压水射流的作用效应和伤害特征着手,分析影响水下高压水射流作业安全的因素,总结各国制订高压水射流作业的安全标准规程现状,提出制订我国水下高压水射流作业安全规程若干认识和设想。 相似文献
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Application of the ALE technique for underwater explosion analysis of a submarine liquefied oxygen tank 总被引：1，自引：0，他引：1
The design of submarines has continually evolved to improve survivability. Explosions may induce local damage as well as global collapse to a submarine. Therefore, it is important to realistically estimate the possible damage conditions due to underwater explosions in the design stage. The present study applied the Arbitrary Lagrangian–Eulerian (ALE) technique, a fluid–structure interaction approach, to simulate an underwater explosion and investigate the survival capability of a damaged submarine liquefied oxygen tank. The Lagrangian–Eulerian coupling algorithm, the equations of state for explosives and seawater, and the simple calculation method for explosive loading were also reviewed. It is shown that underwater explosion analysis using the ALE technique can accurately evaluate structural damage after attack. This procedure could be applied quantitatively to real structural design. 相似文献
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An experiment on the correction of underwater images distorted by waves at the air-water interface was conducted using a laboratory modeling installation intended for experimental examination of light and image transfer across a water surface covered with waves. A digital color camera was used for the simultaneous formation of the image of the underwater test object through the disturbed surface and of the superimposed glitter pattern. Both images are spectrally separated. Processing the glitter pattern makes it possible to obtain the values of the surface slopes at a limited number of points and to use these slopes for retrieval of image fragments. The total corrected image is formed by integration of about 300 partially corrected fragments. This image is close to that obtained through a wave-free water surface. 相似文献