本文選題：輸水管道 + 流固耦合　； 參考：《哈爾濱工業(yè)大學》2016年碩士論文

【摘要】：輸水管道中存在由于流體與管道之間相互作用的流固耦合現(xiàn)象,由于流體流動狀態(tài)的不穩(wěn)定,導致流體內部壓力失衡而產(chǎn)生了壓力波動從而引發(fā)管道的振動,這種振動對于彎頭、閥門等管道的連接部位的影響,會導致管道漏失現(xiàn)象的發(fā)生,在極端情況下可能會發(fā)生爆管事故。從保障輸水管道安全性的角度出發(fā),本文基于流固耦合理論,對重力流、壓力流兩種不同供水方式展開研究,通過對穩(wěn)態(tài)振動數(shù)據(jù)、關閥試驗壓力數(shù)據(jù)的采集,以及數(shù)值模擬技術的應用,來監(jiān)測管道流固耦合振動的特性。首先建設了試驗管道系統(tǒng),有機玻璃管作為管材,由高低位水箱、重力流管道、壓力流管道組成,管道總長度75m,管道內通過水泵和閥門調節(jié)流速在0-2.3m/s之間,在模擬氣液兩相流流體時,用氣泵加氣,加氣量在0-1.5m3/h之間。在兩條管道中,含有上升管段、下降管段、水平管段來模擬輸水管道由于地形起伏而存在多種傾斜度管段的情況。設置電動蝶閥控制流速來進行穩(wěn)態(tài)振動試驗分析,用加速度傳感器采集振動數(shù)據(jù);通過氣動蝶閥的迅速關閉來模擬關閥水錘試驗,用壓力傳感器采集水錘壓力變化數(shù)據(jù)。對試驗數(shù)據(jù)進行理論分析和處理結果表明,對于穩(wěn)態(tài)振動試驗,在單相流中,管道內徑向振動強度較小,而軸向振動強度隨著流速增加而增加,在氣液兩相流中,由于氣體的存在導致管道振動情況變得復雜,下降管段處管道振動受含氣率的影響很大,對比單相流,在相同流速下,軸向振動和徑向振動強度都較大,說明了水中氣體的存在會使管道在穩(wěn)態(tài)情況下振動更加劇烈,不利于管道穩(wěn)定運行。對于關閥水錘壓力試驗,關閥水錘的水錘升壓值隨著流速增加而增加,而在相同流速下,隨著加氣量的增加,關閥水錘升壓值減小,這是由于氣液兩相流中氣體的可壓縮性,有效的減弱了關閥水錘的強度。說明在極端情況流態(tài)變化的情況下,流體中氣體的存在會對管道產(chǎn)生一定的保護作用。在數(shù)值模型分析中,通過ANSYS Workbench平臺進行關閥試驗數(shù)值模擬研究。通過建立與試驗管道情況類似的物理模型進行單向流固耦合數(shù)值分析,得到了管道流體壓力變化云圖及管壁形變變化云圖,對水錘現(xiàn)象有了更加直觀的分析。通過對輸水管道中流固耦合現(xiàn)象多角度,多工況的全面分析,總結了輸水管道流固耦合振動特點,這些試驗數(shù)據(jù)與結論對輸水管道的設計、管理提供了理論基礎,具有一定的參考價值。
[Abstract]:The fluid-solid coupling phenomenon exists in the pipeline because of the interaction between the fluid and the pipeline. Because of the instability of the fluid flow state, the internal pressure of the fluid is out of balance and the pressure fluctuates, which leads to the vibration of the pipeline. The effect of this vibration on the connection part of the pipe, such as elbows and valves, will lead to the leakage of the pipe, and in extreme cases, the pipe burst may occur. From the point of view of ensuring the safety of water conveyance pipeline, based on the theory of fluid-solid coupling, this paper studies two different water supply modes, gravity flow and pressure flow, through the collection of steady state vibration data and valve closing test pressure data. And the application of numerical simulation technology to monitor the characteristics of fluid-solid coupling vibration of pipeline. First of all, the test pipe system was built, and the plexiglass pipe was used as the pipe material, which was composed of high and low water tank, gravity flow pipe and pressure flow pipe. The total length of the pipe was 75m. The flow velocity was adjusted between 0-2.3m/s by water pump and valve in the pipeline. In the simulation of gas-liquid two-phase flow, the gas pump is used to aerate and the amount of gas added is between 0-1.5m3/h. In the two pipelines, there are ascending, descending and horizontal pipe sections to simulate the situation that there are many kinds of inclined pipe segments due to the topographic fluctuation of the pipeline. Setting the electric butterfly valve to control the velocity to carry on the steady state vibration test analysis, using the acceleration sensor to collect the vibration data, through the pneumatic butterfly valve to close quickly to simulate the shutoff valve water hammer test, use the pressure sensor to collect the water hammer pressure change data. The theoretical analysis and processing results of the experimental data show that, for steady state vibration test, the radial vibration intensity in the single phase flow is small, while the axial vibration intensity increases with the increase of the flow velocity, and in the gas-liquid two-phase flow, the axial vibration intensity increases with the increase of the velocity of flow. Due to the existence of gas, the pipeline vibration becomes more complicated, and the pipeline vibration at the descending section is greatly affected by the gas content. Compared with the single-phase flow, the axial vibration and radial vibration intensity are larger at the same flow velocity. It is shown that the existence of gas in water will make the pipe vibration more intense under steady state, which is not conducive to the steady operation of the pipeline. For the shutoff valve water hammer pressure test, the water hammer pressure rise value of the shutoff valve water hammer increases with the increase of the velocity of flow, while at the same velocity, with the increase of the amount of gas added, the pressure rise value of the shutoff valve water hammer decreases because of the compressibility of the gas in the gas-liquid two-phase flow. Effectively weakens the strength of the shutoff water hammer. It shows that the existence of gas in the fluid will protect the pipeline in extreme case. In the numerical model analysis, the numerical simulation of closing valve test is carried out through ANSYS Workbench platform. By establishing a physical model similar to that of the experimental pipeline, the unidirectional fluid-solid coupling numerical analysis is carried out, and the cloud diagram of the fluid pressure variation and the deformation change of the pipe wall are obtained, and the water hammer phenomenon is analyzed more intuitively. Through the comprehensive analysis of fluid-solid coupling phenomenon in water conveyance pipeline from many angles and working conditions, the characteristics of fluid-solid coupling vibration in water conveyance pipeline are summarized. These experimental data and conclusions provide a theoretical basis for the design and management of water conveyance pipeline. It has certain reference value.
【學位授予單位】：哈爾濱工業(yè)大學
【學位級別】：碩士
【學位授予年份】：2016
【分類號】：TV134
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本文編號：1956066