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射流式冲击器改型设计及MATLAB仿真计算

The Retrofic Design of Fluid Efflux Hammer and Its MATLAB Simulation Computation

【作者】 谭凡教

【导师】 殷琨;

【作者基本信息】 吉林大学 , 地质工程, 2005, 博士

【摘要】 分析了射流式冲击器在中国大陆科学钻探工程(CCSD)中应用试验中出现的问题,设计改型了现有的89 型射流式冲击器。改型设计是增加了元件保护、流体分流、蓄能、补流等结构,改变了内管结构形式及其密封方式、装配方式,并改变了原伸缩接头防空打机制。在设计结构基础上,应用射流理论、流体力学理论等对元件流场进行理论分析,经分析得出元件附壁侧和非附壁侧各自排空道、输出道,信号道、出口的流体压力,流速等变量的控制方程。同时,分析得出了带补流孔和蓄能缓冲弹簧的冲击系统活塞运动的控制方程。应用MATLAB 语言及其主要工具Simulink 对元件和冲击器冲击系统进行仿真计算。经过编写m 文件和s-函数计算,计算得出了元件的空载和带载状态下的各个出口的流体状态数值解;对带有弹簧蓄能机构和补流孔的冲击器系统的结果表明,弹簧缓冲蓄能机构和补流孔对活塞回程冲击阶段作用很大。

【Abstract】 Fluid Efflux Hammer has a good name in the field of drilling forits particular style and specific performance, from its burning.However, in the application process, with the changing of workingcondition and specific operating requirement, its advantageswas not made full use, and some interior structure membersaccumulated some questions when applicated.Based on the call of times for Fluid Efflux Hammer, the paperanalyzes the questions when test in CCSD, makes a design to retrofitsome parts of the exiting 89-type Fluid Efflux Hammer, addsstructure to protect Bi-stable Fluidic Element and to shuntexcess flow, designs a structure to storage and buffer hammer,improves feeder current holes, changes the type of the exitinginside tube or inner casing and its sealing, assembling way,modifies the original expansion joint to change the method ofprevent from impacting empty.On the base of design, the paper makes an analyzing the keystructure-Bi-stable Fluidic Element, using jet current theory, fluidmechanics principle, .etc, to computer its flow field parameters, and getthe flow and pressure controlling functions of attachment andno-attachment side`s evacuating way, outputting way, signal way, outlet,etc. At the same time, making reference with Newton`s laws of motionand fluid mechanics principles, the paper analyzes to get the piston`stheoretical moving controlling functions of the impaction system withfeeder current holes and the storage and buffering structure, invariant moving steps. The paper Uses MATLAB language and its major tool-Simulinkto simulate the element and hammer`s impacting system. Aftercomposing m file and s function and simulating, majorconclusions are following: 1.Passing the attachment point ,the fluid jet is still very thin; 2.With the improving controlling flow, the jet`s declinationangle was the vest effected, the arc length of center line wasdecreased, but the amplitude was little; the arc radius decreasedmore quickly. 3.When the element worked normally, the signal way at theattachment and no-attachment size had flow circulating. At theattachment size, the flow velocity was 0.4801m/s, whileno-attachment size, the flow velocity was 1.2453m/s. 4.When working normally, the pressure at no-attachmentvaried slowly, which do advantage to element attaching stably.When switching, the pressure enlarged firstly and thendecreasing. 5.When working normally, the jet`s entraining flow comes fromthat signal flow and outputting flow. 6.When element switching, the outlet generated water shockpressure, and the pressure was some 5 times more than thegeneral pressure. When the pressure reached signal way, thesignal way created shock pressure too, which was 25-30 timesmore than the general one. So large flow ejected out of the signalspout , which made jet fluid generate large declination angle andbended the flow line. At the same time, large flow filled up thegeneral low-pressure eddy zone, which increased the eddy stresssteeply. When the eddy stress exceeded the pressure outsize thejet flow, and maintained for a little time, the jet stream wasattached to the other side of element stably. So we canconcluded, the jet`s switchment was the combined result of themomentum of jet from signal spout and the eddy flow. 7.The simulating result of the impacting system with storageand buffering structure and feeder current holes indicated: In thecase of returning, when piton passed feeder current holes, whichconnected the upside pressure cavity with the outsize one, theflow in the upsize cavity leaked off from feeder current holes, asreduced largely the piston`s returning resistance. For returningresistance decreased, piston got large moving velocity whenleaved holes. And this velocity was stowaged by thestorage-buffering spring. For contacted to the spring, the velocityof piston varied severely, which resulted the flow velocitychanging suddenly which created the stroke pressure to switchover. The huge stroke stress was storage by the spring. Itindicated that feeder current holes play important role in reducingthe piston`s returning resistance, decreasing returning time, andincreasing stroke frequency. Switching over, the pressure downside cavity decreased, thestorage and buffering spring began to released its energy tomotivate piston stroking. So piston got a huge acceleration at thebeginning of stroking case. For spring activated the piston tosome case, element needed to drive the still piston, as that theoutlet had a high speed at the beginning. After storage energyexhausted, piston reached the feeder current holes. Computingresult said now the upside flow did not keep up with piston, so

  • 【网络出版投稿人】 吉林大学
  • 【网络出版年期】2005年 06期
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