Jet formation and penetration performance of a double-layer charge liner with chemically-deposited tungsten as the inner liner

This paper proposes a type of double-layer charge liner fabricated using chemical vapor deposition(CVD)that has tungsten as its inner liner.The feasibility of this design was evaluated through penetration tests.Double-layer charge liners were fabricated by using CVD to deposit tungsten layers on the inner surfaces of pure T2 copper liners.The microstructures of the tungsten layers were analyzed using a scanning electron microscope(SEM).The feasibility analysis was carried out by pulsed X-rays,slug-retrieval test and static penetration tests.The shaped charge jet forming and penetration law of inner tungsten-coated double-layer liner were studied by numerical simulation method.The results showed that the double-layer liners could form well-shaped jets.The errors between the X-ray test results and the numerical results were within 11.07%.A slug-retrieval test was found that the retrieved slug was similar to a numerically simulated slug.Compared with the traditional pure copper shaped charge jet,the penetration depth of the double-layer shaped charge liner increased by 11.4% and>10.8% respectively.In summary,the test results are good,and the numerical simulation is in good agreement with the test,which verified the feasibility of using the CVD method to fabricate double-layer charge liners with a high-density and high-strength refractory metal as the inner liner.

Integrated design and control technology of liner completion and drilling for horizontal wells

Aiming at the problems of large load of rotation drive system,low efficiency of torque transmission and high cost for operation and maintenance of liner steering drilling system for the horizontal well,a new method of liner differential rotary drilling with double tubular strings in the horizontal well is proposed.The technical principle of this method is revealed,supporting tools such as the differential rotation transducer,composite rotary steering system and the hanger are designed,and technological process is optimized.A tool face control technique of steering drilling assembly is proposed and the calculation model of extension limit of liner differential rotary drilling with double tubular strings in horizontal well is established.These results show that the liner differential rotary drilling with double tubular strings is equipped with measurement while drilling(MWD)and positive displacement motor(PDM),and directional drilling of horizontal well is realized by adjusting rotary speed of drill pipe to control the tool face of PDM.Based on the engineering case of deep coalbed methane horizontal well in the eastern margin of Ordos Basin,the extension limit of horizontal drilling with double tubular strings is calculated.Compared with the conventional liner drilling method,the liner differential rotary drilling with double tubular strings increases the extension limit value of horizontal well significantly.The research findings provide useful reference for the integrated design and control of liner completion and drilling of horizontal wells.

3D Roughness Prediction Modeling and Evaluation of Textured Liner of Piston Component-Cylinder System

In this study,a machine vision method is proposed to characterize 3D roughness of the textured surface on cylinder liner processed by plateau honing.The least absolute value(L∞)regression robust algorithm and Levenberg-Marquardt(LM)algorithm are employed to reconstruct image reference plane.On this basis,a single-hidden layer feedforward neural network(SLFNN)based on the extreme learning machine(ELM)is employed to model the relationship between high frequency information and 3D roughness.The characteristic parameters of Abbott-Firestone curve and 3D roughness measured by a confocal microscope are used to construct ELM-SLFNN prediction model for 3D roughness.The results indicate that the proposed method can effectively characterize 3D roughness of the textured surface of cylinder liner.

Machine learning optimization strategy of shaped charge liner structure based on jet penetration efficiency

Shaped charge liner(SCL)has been extensively applied in oil recovery and defense industries.Achieving superior penetration capability through optimizing SCL structures presents a substantial challenge due to intricate rate-dependent processes involving detonation-driven liner collapse,high-speed jet stretching,and penetration.This study introduces an innovative optimization strategy for SCL structures that employs jet penetration efficiency as the primary objective function.The strategy combines experimentally validated finite element method with machine learning(FEM-ML).We propose a novel jet penetration efficiency index derived from enhanced cutoff velocity and shape characteristics of the jet via machine learning.This index effectively evaluates the jet penetration performance.Furthermore,a multi-model fusion based on a machine learning optimization method,called XGBOOST-MFO,is put forward to optimize SCL structure over a large input space.The strategy's feasibility is demonstrated through the optimization of copper SCL implemented via the FEM-ML strategy.Finally,this strategy is extended to optimize the structure of the recently emerging CrMnFeCoNi high-entropy alloy conical liners and hemispherical copper liners.Therefore,the strategy can provide helpful guidance for the engineering design of SCL.

Simulation Study of Solid Rocket Motor C/C Throat Liner Ablation Based on Two Regions

Based on the ablation micro-morphological characteristics, thermo-chemical ablation mechanism, and mechanical stripping mechanism, a dual-region solid rocket motor C/C throat liner ablation model and physical model are established. The ablation program was written and the experimental data of 70 lb BATES engine platform was used for model validation. The relative errors between the simulation calculation results and the experimental results were −6.83% - 10.20%. The ablation program was applied to study the effects of combustion chamber temperature, pressure, oxidation component concentration, throat particle concentration and particle scouring angle on the nozzle throat liner, which provides a reference for the design of the nozzle throat liner and the estimation of solid rocket motor ablation.

磁驱动固体套筒实验模拟中的电流系数

采用不可压缩理论模型,对FP-2装置上开展的磁驱动固体套筒实验进行了模拟分析。模拟结果表明,无论是二维磁流体力学理论模型,还是其他不可压缩理论模型,回流罩结构磁驱动固体套筒的边界磁感应强度公式中都包含一个小于1的套筒电流系数。对不同套筒厚度、不同套筒半径条件下磁驱动固体套筒实验的电流系数进行了模拟,发现电流系数不仅与套筒内半径有关,还与套筒厚度有关;套筒内半径越大,套筒电流系数越小;套筒厚度越大,套筒电流系数越小。准确掌握磁驱动固体套筒电流系数的变化规律,可使磁流体程序从磁驱动固体套筒实验的后验模拟发展为精确预测,使磁流体力学模型真正具备正确设计和指导磁驱动固体套筒相关实验的理论能力。

非对称中空环形聚能装药成型与侵彻特性影响因素分析

为减弱中空环形聚能装药形成的中心侵彻体对后级结构的破坏作用,通过改变环锥罩的偏心距离和壁厚,调整了装药和药型罩的质量分布,使之形成准直环形射流,研究了炸高对环形射流侵彻威力的影响规律。数值模拟结果表明:内壳为铝合金时的中心孔平均侵彻深度较内壳为钢时的平均侵彻深度低36.13%;非偏心环锥罩形成的射流存在径向偏移,侵彻能力较弱。当环锥罩顶向外侧偏移0.05d(d为环形装药厚度)时,射流准直性较好,环形射流侵彻深度较大;随着药型罩壁厚的增加,射流头部速度不断减小,当壁厚为0.045d时,偏心环锥罩形成的环形射流侵彻能力较强;环形射流侵彻深度对炸高较为敏感,在炸高为1.12d时,环形射流侵彻深度较大。针对非偏心环锥罩和偏心环锥罩两种药型罩结构开展的静破甲试验表明,环形射流侵彻深度和扩孔直径的试验结果与数值模拟结果误差小于12%,验证了数值模拟模型的可靠性。

TSL(Thin spray-on liners)材料在巷道支护中的应用

TSL(Thin Spray-on Liners)材料作为一种最新的支护材料,在矿山巷道中开始逐渐得到应用,在某些地区已经作为一种标准支护手段来取代喷网支护。这种大概4mm厚的喷层,能有效的支护松散岩体,增强其他支护结构的作用效果,并能保护锚杆锚网等金属材料免受侵蚀。实验表明,在高地应力情况下,还能有效的减少岩爆的破坏。目前市场上有多种TSL产品,其材料性能及实验手段也在不断的发展完善。本文主要介绍TSL材料在巷道支护中的作用机理及在不同受力状态下材料的性能相关测试实验。

组合-填充药型罩成型及侵彻靶板数值模拟

针对聚能射流侵彻披挂爆炸反应装甲坦克顶部装甲的高效毁伤问题,提出了一种新型的组合-填充药型罩结构。采用非线性动力学分析软件AUTODYN-2D对射流形成和侵彻靶板过程进行了数值模拟,并分析了填充物材料和起爆方式对射流成型的影响以及炸高对侵彻性能的影响。研究结果表明:所提出的组合-填充药型罩可以形成首尾相连的两级串联射流,填充物采用铝和特氟龙时射流成型效果较好,但铝成型更加稳定;点环起爆形成的射流动能比单独点起爆形成的前级射流动能提高67.06%,后级射流动能提高29.51%;在炸高区间为2~6 CD(装药直径)时,成型射流均可以侵彻披挂爆炸反应装甲的坦克顶甲,并保持一定的剩余头部速度,且最佳炸高为5 CD。本研究对反披挂爆炸反应装甲坦克顶甲的新结构药型罩设计具有参考意义。

APPLICATION OF HOT-PRESS SINTERING TECHNIQUE TO EXPLOSIVE CHARGE LINER OF PETROLEUM PERFORATION BULLET

A new method for manufacturing explosive charge liner of petroleum perforation bullet, using hot press sintering technique, has been introduced in the paper. The sintering process of making explosive charge liner has been investigated. The mechanical test and SEM analysis indicate that the property of the liner produced by the process is satisfied.

环形复合内衬头盔冲击波防护性能研究

冲击波防护能力是单兵头盔的主要性能指标,对提高单兵战场生存能力具有重要意义。为了提高单兵头盔的冲击波防护性能,针对先进战斗头盔内衬的结构以及布置方式展开探索,提出环形聚脲-聚氨酯泡沫-海绵复合材料外沿内衬设计,并进行防护性能评估。通过激波管和实爆,针对有/无头盔以及装配不同结构及尺寸外沿内衬头盔的冲击波防护性能展开测试,对前额、颅顶及后脑3个重点区域位置表面的冲击波波形以及压力峰值进行对比分析。实验结果表明:佩戴头盔后冲击波主要通过头-头盔间隙以绕射的形式进入并作用于头部表面,间隙内冲击波聚集叠加反而可能会使压力增强,且由于叠加汇聚效应往往导致距离爆源较远的位点,容易形成局部高压区;环形聚脲-聚氨酯泡沫-海绵复合材料外沿内衬可以有效阻挡绕射波进入头盔内部、减弱绕射波叠加效应,各测点冲击波超压衰减率均可达40%以上;在所采用的入射冲击波(弱冲击波)条件下,冲击波作用过程中形成的间隙越小,防护效果越好;当聚脲-聚氨酯泡沫材料宽度为15 mm时外沿内衬与头模贴合程度最好且防护效果最优,外场爆炸实验结果显示,前额、颅顶和后脑位置超压衰减率分别可高达92.26%、88.82%和87.19%。

包覆式活性EFP成型机理与规律研究

为研究包覆式活性爆炸成型弹丸(Explosively Formed Projectiles,EFP)成型机理及药型罩结构对成型行为的影响规律,采用Lagrange和Euler组合算法开展包覆式活性EFP成型过程数值模拟。数值模拟结果首先揭示包覆式活性EFP成型机理,其典型包覆成型过程主要包括轴向双罩碰撞阶段、径向包覆闭合阶段和金属前驱侵彻体拉伸阶段。在轴向双罩碰撞阶段,双罩通过多次碰撞-分离-碰撞过程,实现轴向加速和动能传递;在径向包覆闭合阶段,金属罩向前折叠,其后部实现对活性罩完全包覆,前部形成速度梯度明显的金属前驱侵彻体;随后,金属前驱侵彻体随时间逐渐拉伸,甚至断裂。进一步得到紫铜罩和活性罩形状参数对包覆成型的影响规律,随紫铜罩边缘厚度从2.0 mm减小到0.5 mm,包覆闭合时间从57.9μs减小到23.9μs,同时头部速度从1851 m/s增大到2370 m/s,侵彻体长度从76 mm增大到110.5 mm;随紫铜罩曲率半径从60 mm减小到40 mm,包覆闭合时间从42.1μs减小到28.1μs,同时头部速度从1789 m/s增大到2242 m/s,侵彻体长度从66 mm增大到100 mm;随活性罩厚度由6 mm减小至2 mm,包覆时间从52.0μs减小至32.1μs,活性罩质量从6.47 g降低至2.37 g;随活性罩直径由32 mm减小至16 mm,包覆时间从34.4μs减小至30.8μs,活性罩质量从6.42 g降低为1.61 g。研究结果可为包覆式活性EFP聚能装药设计提供指导和参考。

Analysis of diffusion-adsorption equivalency of landfill liner systems for organic contaminants

The equivalence between multilayered barriers regarding diffusion and adsorption was studied. The bottom boundary of the liner system is defined by assuming concentration continuous and flux continuous conditions of the contaminant between the bottom liner layer and the underlying soil. Five different liner systems were compared in terms of solute breakthrough time. The results of the analysis showed that breakthrough time of the hydrophobic organic compounds for a 2-meter-thick compacted clay liner （CCL） could be 3-4 orders of magnitude is greater than the breakthrough time for a geosynthetic clay liner （GCL） composite liner. The GM/GCL and GM/CCL composite liner systems provide a better diffusion barrier for the hydrophilic organic compounds than that for the hydrophobic compounds due to their different Henry＇s coefficient. The calculated breakthrough times of the organic contaminants for the Chinese standard liner systems were found to be generally greater than those for the GCL alternatives, for the specific conditions examined. If the distribution coefficient increases to 2.8 for the hydrophobic compounds or 1.0 for the hydrophilic compounds, the thickness of the attenuation layer needed to achieve the same breakthrough time as the standard liner systems can be reduced by a factor of about 1.9-2.4. As far as diffusive and adsorption contaminant transport are concerned, GM or GCL is less effective than CCL.

Effects of Friction Heat on the Tribological Properties of the Woven Self-lubricating Liner

In the dry-sliding process of the woven self-lubricating liner which is used in the self-lubricating spherical plain bearing, the friction heat plays an important role in the tribological performances of the liner. It has important value to study on the relationship between tribological performances of the liner and the friction heat. Unforttmately, up to now, published work on this relationship is quite scarce. Therefore, the effect of friction heat on the tribological performances of the liner was investigated in the present work. The tribological behaviors of the liner were evaluated by using the high temperature end surface wear tester. Scanning electron microscopy （SEM） was utilized to examine the morphologies of worn surfaces of the liner and study the failure modes. Differential scanning calorimetry （DSC） measurement and X-ray diffraction （XRD） analysis were performed to study the behaviors of the wear debris. The temperature rise on the worn surface was calculated according to classical models. SEM observation shows that the dominating wear mechanism for the liner is mainly affected by friction shear force, contact pressure and friction heat. Higher fusion heat for the wear debris than that for the pure polytetrafluroethylene （PTFE） indicates that the PTFE is the main portion of the wear debris, and, the PTFE in the wear debris shows a higher crystallisation degree owing to the effects of friction shear force and the friction heat. Combining the calculated temperature rise results with the wear rate of the liner, it can be concluded that the effects of temperature rise o n the tribological performances of the liner become more obvious when the temperature rise exceeds the glass transition temperature （Tg） of the PTFE. The wear resistance of the liner deteriorates dramatically when the temperature rise approaches to the melting point （Ton） of the PTFE. The tribological performances of the liner can be improved when the temperature rise exceeds Tg but is far lower than Ton- The present study on the relationship between the temperature rise and the tribological performances of the liner may provide the basis for further understanding of the wear mechanisms of the liner as well as the relationship between the formation of the PTFE transfer film and the friction heat during the dry-sliding of the Finer.

Controlling strain in geosynthetic liner systems used in vertically expanded landfills

According to relevant new regulations in China,a composite liner system involving geosynthetic materials must be installed at the bottom of an expanded landfill.The deformation and integrity of the composite liner under a variety of factors are important issue to be considered in the design of a landfill expansion.In this paper,we investigate the strain distribution in geosynthetic materials within the composite liner system of expanded landfills,including strains in geosynthetic materials resulting from overall settlement and lateral movement of landfills,localized subsidence in landfills,and differential settlement around gas venting wells.The allowable strains of geosynthetic materials are discussed based on the results of tensile tests,and the corresponding design criteria for composite liner systems are proposed.Meanwhile,practical measures allowing strain control in geosynthetic materials used in landfill engineering are proposed.

The Friction and Wear Properties of the Spherical Plain Bearings with Self-lubricating Composite Liner in Oscillatory Movement

A test method based on the condition simulation and a friction and wear test machine featuring in oscillatory movement were set up for self-lubricating spherical plain bearings (SPB). In the machine the condition parameters such as load, angle and frequency of oscillation and number of test cycles can be properly controlled. The data relating to the tribological properties of the bearing, in terms of friction coefficient, linear wear amount, temperature near friction surface and applied load, can be monitored and recorded simultaneously during test process by a computerized measuring system of the machine. Efforts were made to improve the measurement technology of the friction coefficient in oscillating motion. In result, a well-designed bearing torque mechanism was developed, which could reveal the relation between the friction coefficient and the displacement of oscillating angle in any defined cycle while the curve of friction coefficient vs number of testing cycles was continuously plotted. The tribological properties and service life of four kinds of the bearings, i.e, the sampleⅠ-Ⅳ with different self-lubricating composite liners, including three kinds of polytetrafluoroethylene (PTFE) fiber weave/epoxy resin composite liners and a PTFE plastic/copper grid composite liner, were evaluated by testing, and the wear mechanisms of the liner materials were analyzed.

Bore-center annular shaped charges with different liner materials penetrating into steel targets

The bore-center annular shaped charge(BCASC)is a new type of shaped charge which can generate a larger-diameter hole in steel targets than classical shaped charges.In this paper,the influence of three liner materials,i.e.molybdenum,nickel and copper,on BCASC formation and penetrating into steel targets was investigated by experiment and numerical simulation.The simulation results were well consistent with the experimental results.This study showed that,at 0.50D standoff distance,the axial velocity of the molybdenum projectile was lower than that of the nickel and copper projectiles.The nickel and copper projectiles had almost the same head velocity.The absolute values of the radial velocity of the molybdenum projectile head was lower than that of the nickel and copper projectiles.However,at 0.75D standoff distance,the absolute values of the radial velocity of the molybdenum projectile head became much greater than that of the nickel and copper projectile heads.The projectile formed by BCASC with the molybdenum liner had the highest penetration depth of 61.5 mm,which was 10.0%and 21.3%higher than that generated by the copper and nickel projectiles.

恒星形成在LINER中的作用(英文)

我们发现利用ＷｏｌｆＲａｙｅｔ 星系的远红外射电相关关系可以对ＬＩＮＥＲ 的激发机制初步分类。非常有意思的一个现象是几乎所有有内环结构的ＬＩＮＥＲ 都是星暴占主导的源，它们的ＡＧＮ 活动比ＡＧＮ 占主导的ＬＩＮＥＲ 要低。我们还发现对年龄大于１０７ 年的星暴星系或复合类天体（ＡＧＮ 和星暴的贡献相当的天体） 来说，激波加热尘埃的机制可能是很重要的。

Impact of consolidation pressure on contaminant migration in clay liner

Consolidation deformation occurs in clay liners under the self-weight of wastes at a simple garbage dump or dredged sediment dump, which leads to a decrease in the porosity. However. the migration of contaminants in clay liners is influenced by the porosity. Thus, the impact of consolidation deformation of clay liners on the migration of contaminants cannot be ignored. Based on Biot＇s consolidation theory, the contaminant migration theory, and consideration of the three kinds of migration mechanisms of convection, diffusion, and adsorption, a one-dimensional migration model of contaminants in deforming porous media was established, and the finite difference method was adopted to obtain the numerical solutions for an established initial-boundary value problem. The impact of consolidation pressure on the migration law of a contaminant was studied. The results show that, regardless of adsorption modes, different consolidation pressures have similar impacts on the migration law of the contaminant. Namely, over a certain migration time, the greater the consolidation pressure is, the smaller the migration depth of the contaminant. The results also show that, while the migration time increases, the impact of a certain increment of consolidation pressure on the variation of contaminant concentration with the depth increases gradually and, while the migration depth increases, the impact of a certain increment of consolidation pressure on the variation of the contaminant concentration with time increases gradually.

Numerical study on magneto-Rayleigh–Taylor instabilities for thin liner implosions on the primary test stand facility

The thin aluminum liners with an aspect ratio R/?r 1 have been imploded on the primary test stand(PTS) facility,where R is the outer radius of the liner and ?r is the thickness. The x-ray self-emission images present azimuthally correlated perturbations in the liner implosions. The experiments show that at-10 ns before the stagnation, the wavelengths of perturbation are about 0.93 mm and 1.67 mm for the small-radius and large-radius liners, respectively. We have utilized the resistive magnetohydrodynamic code PLUTO to study the development of magneto-Rayleigh–Taylor(MRT) instabilities under experimental conditions. The calculated perturbation amplitudes are consistent with the experimental observations very well. We have found that both mode coupling and long implosion distance are responsible for the more developed instabilities in the large-radius liner implosions.