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轻兵器 2024年第5期 3-3页

美国Umarex气枪公司主要生产各种气手枪、气步枪、气枪弹及气枪充气压缩机,hammer是该公司生产的大口径气步枪。其枪管及机匣由钢材制成,枪托及发射机座由Nymax聚合物制成,机匣顶部设有皮卡汀尼导轨,标配光学瞄准镜。

关键词：光学瞄准镜气步枪气手枪气枪弹机匣 hammer 发射机

Computing equations of water hammer in pseudo-homogeneous solid-liquid flow and their verification

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Science China(Technological Sciences) 2000年第2期43卷 215-224页

作者：韩文亮董曾南柴宏恩韩军 Department of Hydraulic and Hydropower Engineering Tsinghua University Beijing China

In engineering practice, single-phase water hammer models are still employed to analyze the water hammer of solid-liquid flow. According to the characteristics of solid-liquid flow, continuity equations and momentum equations of pseudo-homogeneous flows are deduced, and a pseudo-homogeneous water hammer model is thus built and verified with experiment results. The characteristics of solid-liquid flow’s viscosity, resistance and wave velocity are considered in the model. Therefore, it has higher precision than a single-phase model.

关键词： water hammer model single-phase flow pseudo-homogeneous solid-liquid flow continuity equation momentum equation.

Water hammer in pipelines with hyperconcentrated slurry flows carrying solid particles

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Science China(Technological Sciences) 1998年第4期41卷 337-347页

作者：韩文亮董曾南柴宏恩 Department of Hydraulic Engineering Tsinghua University Beijing China

Water hammers in pseudo-homogeneous flows and heterogeneous flows have been investigated, and equations for the wave propagation speed and the additional pressure due to water hammer in both flows have been developed.... 详细信息

关键词： water hammer slurry pseudo-homogeneous flow heterogeneous flow wave propagation speed.

Energy transmission of down hole hammer tool and its conditionality

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中国有色金属学会会刊：英文版 2000年第1期10卷 109-113页

作者：李夕兵中南工业大学湖南长沙 University of Missouri-Rolla 美国

By analyzing the efficiency of transmission of impact energy in down hole hammers and its affecting factors, it has been revealed that the percussive action of down hole hammers can greatly increase the rate of penetration in shallow well drilling, but its efficiency will be deeply decreased in very deep well drilling. Further analysis showed that there exists a reasonable mass matching of the piston to the bit for different formations. Meanwhile, in an effort to effectively transmit the impact energy from rotary percussive drilling, it is suggested that the roller conical bits widely used in petroleum industry and the recently developed flat fixed PDC bits should be changed into parabolic fixed diamond enhanced bits.

关键词： down hole hammer bit design impact energy efficiency

Numerical Simulation for Two-Phase Water hammer Flows in Pipe by Quasi-Two-Dimensional Model

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Journal of Harbin Institute of Technology(New Series) 2016年第2期23卷 9-15页

作者： Tae Uk Jang Yuebin Wu Ying Xu Qiang Sun School of Municipal and Environmental Engineering Harbin Institute of Technology Department of Mechanics Kim Il Sung University State Key Laboratory of Urban Water Resource and Environment Harbin Institute of Technology School of Energy and Architecture Harbin University of Commerce

The features of a quasi-two-dimensional( quasi-2D) model for simulating two-phase water hammer flows with vaporous cavity in a pipe are investigated. The quasi-2D model with discrete vaporous cavity in the pipe is proposed in this paper. This model uses the quasi-2D model for pure liquid zone and one-dimensional( 1D) discrete vapor cavity model for vaporous cavity zone. The quasi-2D model solves two-dimensional equations for both axial and radial velocities and 1D equations for both pressure head and discharge by the method of characteristics. The 1D discrete vapor cavity model is used to simulate the vaporous cavity occurred when the pressure in the local pipe is lower than the vapor pressure of the liquid. The proposed model is used to simulate two-phase water flows caused by the rapid downstream valve closure in a reservoir-pipe-valve system.The results obtained by the proposed model are compared with those by the corresponding 1D model and the experimental ones provided by the literature,respectively. The comparison shows that the maximum pressure heads simulated by the proposed model are more accurate than those by the corresponding 1D model.

关键词： water hammer method of characteristics quasi -two -dimensional model column separation discrete vapor cavity model

Structure Parameters Optimization Analysis of Hydraulic hammer System

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Modern Mechanical Engineering 2012年第4期2卷 137-142页

作者： Guoping Yang Jian Fang College of Automotive Engineering Shanghai University of Engineering and Science Shanghai China

In order to improve the impact performance, the structure of hydraulic hammer should be optimized. In this paper, the ranges of eight vital structure parameters of piston and reversing valve system of hydraulic hammer were selected firstly;and then found the best value of different parameters under experiments with the method of computer optimization and the parametric analysis method provided by ADAMS software. These methods worked and the best design values of parameters of hydraulic hammer were obtained. At last, the optimal impact energy of virtual prototype of hydraulic breaking hammer was calculated and compared with the original impact performance. The results reveal that impact performance of hydraulic hammer has been improved significantly.

关键词： Hydraulic hammer Structure Parameters Optimization Analysis Impact Performance ADAMS

基于hammer的斗门水库引水管水力过渡分析

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陕西水利 2022年第5期 178-180,186页

作者：刘帮超陕西省水利电力勘测设计研究院陕西西安710000

根据陕西省斗门水库引水管线的实际情况,采用hammer水力过渡分析软件对管线的水锤动态进行计算分析。结果显示,在长距离重力输水管线中为保障管道安全运行,在末端控制阀门旁安装旁通阀控制关阀时间,可有利于控制水锤高低压力值,有利于... 详细信息

根据陕西省斗门水库引水管线的实际情况,采用hammer水力过渡分析软件对管线的水锤动态进行计算分析。结果显示,在长距离重力输水管线中为保障管道安全运行,在末端控制阀门旁安装旁通阀控制关阀时间,可有利于控制水锤高低压力值,有利于工程运行安全。

关键词：水力过渡重力流 hammer 长距离供水

Numerical solution for dynamics of pneumatic DTH hammer system

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探矿工程（岩土钻掘工程） 2009年第S1期36卷 170-176页

作者： QU Yegao,BU Changgen,LIU Baolin,Lian Yinjun(China University of Geosciences,Beijing 100083,China) China University of Geosciences Beijing 100083China

The pneumatic down-the-hole(DTH) hammer is one of the efficient equipments used in medium hard to very hard rock drilling frield,and any change in its structure design affects all performance parameters of a pneuamtic DTH hammer directly.Yet,owing to the complexity of the dynamic interaction among the components in DTH hammer systems,until now it has been difficult to obtain reliable estimates of the design parameter affects.Thus providing an design parameter optimization and the layout of dynamics behavior of DTH hammer is of great importance.This paper documents the development and solution of a computational model for the dynamic response of a pneumatic DTH hammer.The model consists of rigid piston dynamics equation and chamber thermodynamics equations.The resulting model represented by a set of coupled nonlinear differential equations were computed in Visual C++ program.The developed solutions are used to perform a parametric study to illustrate the inffluence of the piston mass and supply pressure on the impact performance of DTH hammer system.

关键词： simulation Impact down-the-hole(DTH) hammer

AN ANALYTICAL FORMULA FOR CALCULATING WATER hammer IN CONDUIT OF HYDRAULIC TURBINE

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Chinese Science Bulletin 1980年第3期25卷 248-254页

作者：段昌国 Beijing Graduate Research Division North China Institute of Water Conservancy and Hydropower Engineering

When the phase number of the water hammer wave is greater than 4—6, we generally adopt the rigid water column theory. Based on this theory, Allievi has given a formula to solve the water hammer for uniform gate closu... 详细信息

关键词： hammer inconsistent closure adopt rigid fitting instant pipe turbine hydraulic

Encapsulated Water hammer: Theoretical/Experimental Study

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World Journal of Engineering and Technology 2015年第3期3卷 290-295页

作者： Geanette Polanco Muhammad Shakeel Virk Umair N. Mughal Sojo Victor Da Paixao José Vidal Antonio Aguillón Orlando Atmospheric Icing Research Team Industrial Engineering Department Narvik University College Narvik Norway Industrial Department Simon Bolivar University Caracas Venezuela

Water hammer phenomenon involves the transformation of kinetic energy in pressure energy, this transformation occurs as the fluid conditions change inside the pipe in quite a short time. Industry requires to affront frequent flow interruptions in pipe systems due to the closing of valves or stopping of pumping equipment. This phenomenon can initiate serious damages like destruction of the pipe system involving leakage of the working fluid to the environment. If the system operates in a fragile environment, as in cold regions, concern about the consequences of leakage increases due to the variation of physical properties of fluid as well as the pipe material as a function of the temperature. Water hammer effects can be controlled focusing efforts on reducing the pressure increment that takes place once the phenomenon is presented. Some methods try to reduce the time of closure or the rate of change before the closure using special valves, others install additional elements to absorb the pressure surge and dissipate energy, others install relief valves to release the pressure, and others try to split the problem is smaller sections by installing check valves with dashpot or non-return valves. Splitting the pipeline into shorter sections is often used to help preventing the pipeline length of water falling back after a pump stops. In this paper the numerical results of maximum and minimum pressure values at both ends of a closed section are compared to experimental data. The numerical results follow the experimental trends.

关键词： Water hammer Encapsulated Section Experimental Facilities Cold Regions