您现在的位置: 首页> 研究主题> shock wave

shock wave

shock wave的相关文献在1996年到2022年内共计61篇,主要集中在自动化技术、计算机技术、力学、教育 等领域,其中期刊论文61篇、相关期刊48种,包括山东工商学院学报、中国医学教育技术、农村青少年科学探究等; shock wave的相关文献由128位作者贡献,包括元成、叶文胜、周源等。

shock wave—发文量

期刊论文>

论文:61 占比:100.00%

总计:61篇

shock wave—发文趋势图

shock wave

-研究学者

  • 元成
  • 叶文胜
  • 周源
  • 王昭英
  • 郑泳
  • Abdulsalam Hatem Nawar
  • Abhinandan Gupta
  • Acwell
  • Ahsan Ali
  • Akshyaya Pradhan
  • 期刊论文

搜索

排序:

年份

    • 李琛; 韩若愚; 刘毅; 赵锦林; 王亚楠; 何锋; 欧阳吉庭
    • 摘要: This work deals with an experimental study of a Cu planar wire array(PWA)in air and water under the stored energy 300-1200 J.A single Cu wire is adopted as a controlled trial.Four configurations of PWA and a wire with the same mass(cross-section area)but the different specific surface areas(15-223 cm^(2)g^(-1))are exploded.The transient process is analyzed using high-speed photography in combination with the results of optical emission and discharge.Discharge characteristics revealed that PWA always has a higher electric power peak,early but higher voltage peak,as well as faster vaporization and ionization process than the single-wire case.Two to three times stronger optical emission could be obtained when replacing the single-wire with PWA,indicating a higher energy-density state is reached.Phenomenologically,in both air and water,single-wire load tends to develop a transverse stratified structure,while PWA is dominated by the uneven energy deposition among wires.Finally,the synchronism and uniformity of the PWA explosion are discussed.
    • Keqi YE; Yuelin ZHAO; Feng WU; Wanxie ZHONG
    • 摘要: The numerical oscillation problem is a difficulty for the simulation of rapidly varying shallow water surfaces which are often caused by the unsmooth uneven bottom,the moving wet-dry interface,and so on.In this paper,an adaptive artificial viscosity(AAV)is proposed and combined with the displacement shallow water wave equation(DSWWE)to establish an effective model which can accurately predict the evolution of multiple shocks effected by the uneven bottom and the wet-dry interface.The effectiveness of the proposed AAV is first illustrated by using the steady-state solution and the small perturbation analysis.Then,the action mechanism of the AAV on the shallow water waves with the uneven bottom is explained by using the Fourier theory.It is shown that the AVV can suppress the wave with the large wave number,and can also suppress the numerical oscillations for the rapidly varying bottom.Finally,four numerical examples are given,and the numerical results show that the DSWWE combined with the AAV can effectively simulate the shock waves,accurately capture the movements of wet-dry interfaces,and precisely preserve the mass.
    • 张江波; 高红旭; 肖飞; 刘威; 梁泰鑫; 马中亮; 吴坚
    • 摘要: In order to study the effect of shock wave formation on propellant ignition in capillary discharge,the shock wave formation process was analyzed using experimental and theoretical methods;the plasma jet temperature was measured,and closed bomb and 30 mm gun experiments were carried out.The results show that the first shock wave has a smaller value and larger range of influence,while the second shock wave has a larger value and smaller range of influence.A plasma jet can generate a shock wave at the nozzle according to the calculated plasma pressure and velocity,which is well confirmed by experiments and calculations.The plasma jet temperature is high during the formation of a shock wave and then decreases sharply.Plasma ignition can increase the burning rate of a propellant by about 30%by increasing the burning surface area of the propellant.Compared to conventional ignition,the average maximum chamber pressure and average muzzle velocity of plasma ignition are increased by 9.1 MPa and29.3 m·s^(-1)(~3%),respectively,in a 30 mm gun.Plasma ignition has strong ignition ability and short ignition delay time due to the generation of a shock wave.By increasing the burning rate of the propellant,the muzzle velocity can be greatly improved when the maximum chamber pressure increases a little.The characteristics of the shock wave can be applied in the application of the capillary discharge plasma.For example,it can be applied in fusion,launching and combustion.
    • Akshyaya Pradhan; Pravesh Vishwakarma; Monika Bhandari; Rishi Sethi
    • 摘要: BACKGROUND Coronary calcium poses a challenge for the interventional cardiologist often leading to stent under-expansion and subsequent ischemic events.Aggressive balloon post-dilatation though helpful is usually inadequate.Multiple plaque ablation techniques are in vogue,but they are technically demanding and are not without complications.Shockwave intravascular lithotripsy(S-IVL)has emerged as a user-friendly and effective mechanism for calcium management with a high safety margin.A series of trials(DISRUPT CAD I-IV)have demonstrated both short-term and long-term safety and efficacy of the technique.As experience with the technique grows more and more,therapy areas like stent restenosis are being covered by the S-IVL.CASE SUMMARY We report a series of 2 cases successfully managed with S-IVL therapy at our center.The first case is of a 57-year-old smoker who presented with acute coronary syndrome.His left anterior descending coronary artery revealed calcified 90%stenosis on angiogram and a combination of superficial-deep calcium on intracoronary imaging.The calcium was treated with 20 pulses of S-IVL to create discontinuity and a sirolimus eluting drug-eluting stent was successfully implanted.The second case is that of an elderly lady who presented with stable angina and demonstrated diffuse calcified lesions in the left anterior descending artery on angiogram.She also demonstrated a mixture of superficial and deep seated calcium zones on imaging.S-IVL therapy was applied to generate fractures in calcium,and two overlapping drug-eluting stents were implanted successfully without any complications.CONCLUSION S-IVL is an emerging,efficient,user-friendly and safe therapy for managing intracoronary calcium in routine interventional practice.
    • Mwanamputu Mbwanzo; Timothée Nsongo; Pasi Bengi Masata Andre; Flory Lidinga Mobonda; Mathurin Gogom
    • 摘要: This article focuses on the aggression of lightning overload on the equipment of the electrical network of sites where storm activity is very dense;and the electrocution of people located in the direct environment of the high-voltage substation during the flow of lightning current to the ground through the ground socket. The modeling of the flow circuit of the shock wave consisting of guard wire, lightning arrester and ground socket couple to the transformer of the high voltage substations, thanks to the approach of a servo block, led to the synthesis of a PID regulator (corrector) whose action is to reject the effects of the overvoltage on the network equipment and to significantly reduce or even cancel the effects of the step or touch voltage due to the distribution of the potential around the ground socket;and thus improve the quality of service of the high-voltage transmission and distribution electricity network, especially in stormy times.
    • R. Hemel; M. T. Azam; M. S. Alam
    • 摘要: This paper deals with the Burgers equation which is the most common model used in the nonlinear conservation laws. Here the theoretical aspect of conservation law is discussed by using inviscid Burgers equation. At first, we introduce the general non-linear conservation law as a partial differential equation and its solution procedure by the method of characteristic. Next, we present the weak solution of the problem with entropy condition. Taking into account shock wave and rarefaction wave, the Riemann problem has also been discussed. Finally, the finite volume method is considered to approximate the numerical solution of the inviscid Burgers equation with continuous and discontinuous initial data. An illustration of the problem is provided by some examples. Moreover, the Godunov method provides a good approximation for the problem.
    • 赵育良; 袁涛
    • 摘要: 提出了一种基于飞行参数实现某型教练机仪表实时仿真回放的方法.该方法在飞参数据的解码和预处理的基础上,采用Flash实现虚拟仪表面板的图形化和动态仿真设计,利用C#开发平台结合ShockWave控件,通过飞参数据驱动仪表实时地进行仿真回放.该系统的使用,对飞行事故调查、飞行质量的监控都有着重大意义,为飞行训练提供了有力的保障.
    • Bin Wang; Jing Zheng; Yuanyuan Yu; Runmin Lv; Changyue Xu
    • 摘要: Rocket sleds belong to a category of large-scale test platforms running on the ground.The applications can be found in many fields,such as aerospace engineering,conventional weapons,and civil high-tech products.In the present work,shock-wave/rail-fasteners interaction is investigated numerically when the rocket sled is in supersonic flow conditions.Two typical rocket sled models are considered,i.e.,an anti-D shaped version of the rocket sled and an axisymmetric slender-body variant.The dynamics for Mach number 2 have been simulated in the framework of a dynamic mesh method.The emerging shock waves can be categorized as head-shock,tailing-shock and reflected-shock.An unsteady large-scale vortex and related shock dynamics have been found for the anti-D shaped rocket sled.However,a quasi-steady flow state exists for the slender-body shaped rocket sled.It indicates that the axisymmetric geometry is more suitable for the effective production of rocket sleds.With the help of power spectral density analysis,we have also determined the characteristic frequencies related to shock-wave/rail-fasteners interaction.Furthermore,a harmonic phenomenon has been revealed,which is intimately related to a shock wave reflection mechanism.
    • Tian Li; Xiaohan Zhang; Yao Jiang; Weihua Zhang
    • 摘要: The so-called Evacuated Tube Train(ETT)is currently being proposed as a high-speed transportation system potentially competitive with airplane transportation.Aerodynamic resistance is one of the most crucial factors for the successful design of an ETT.In the present work,a three-dimensional concept ETT model has been elaborated.The aerodynamic characteristics of the subsonic ETT have been numerically simulated under different conditions.The train’s running speed varies from 600 km/h up to 1200 km/h,and the blockage ratio is in the range between 0.1 and 0.3.As the blocking ratio and running speed increase,the resistance of the head car increases greatly,while the resistance of the middle car changes slightly.The aerodynamic resistance of the tail car is affected by the shock wave emerging in the wake flow.Two different design criteria for the maximum allowed aerodynamic resistance are proposed for aerodynamic parameter matching.With an increase in the blockage ratio and running speed,the atmospheric pressure in the tube should be decreased to achieve a balance.
    • Kyung Jin Lee; Jin Ik Park; Soo Yeon Oh
    • 摘要: Obesity, particularly abdominal obesity, increases the risk of cardiovascular disease (CVD). This study investigates the effects of six-week (twice a week, 12 sessions total) extracorporeal shockwave therapy (SWT) and hand massage therapy (HT) on body composition and serum lipids in overweight and obese Korean women aged between 35 and 59, according to their serum cholesterol level (≥200 mg/dL versus <200 mg/dL). After the program, weights decreased significantly in both the HT Group and SWT Group (p < 0.05);weights of those with cholesterol < 200 mg/dL significantly decreased in the HT Group (p = 0.038), while weights of those with cholesterol ≥ 200 mg/dL significantly decreased in the SWT Group (p = 0.001). BMIs decreased significantly in both the HT Group and the SWT Group (p < 0.05);BMIs of those with cholesterol < 200 mg/dL significantly decreased in the HT Group (p = 0.018), while BMIs of those with cholesterol ≥ 200 mg/dL significantly decreased in the SWT Group (p = 0.001). The body fat percentage of subjects significantly decreased only in the SWT Group (p = 0.027);the waist-hip ratio significantly decreased only in HT Group (p = 0.034). Serum cholesterol levels significantly decreased in those with cholesterol < 200 mg/dL in the HT Group (p < 0.05) and those with cholesterol ≥ 200 mg/dL in SWT Group (p = 0.055). Triglyceride significantly decreased in both those with cholesterol < 200 mg/dL and those with cholesterol ≥ 200 mg/dL, but did not significantly decrease in either subgroup of the HT Group. The study results suggest that SWT is effective in improving body measurements and serum lipids in those with cholesterol ≥ 200 mg/dL, while HT therapy is effective in those with cholesterol < 200 mg/dL. In conclusion, SWT and HT improved abdominal obesity by reducing body weight and waist circumference and helped improving serum lip index, suggesting the benefit for managing body measurements and serum lipids of overweight and obese individuals.
  • 查看更多

客服邮箱:kefu@zhangqiaokeyan.com

京公网安备:11010802029741号 ICP备案号:京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有
  • 客服微信

  • 服务号