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天然气管道泄漏声场特性研究 被引量:8
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作者 徐晴晴 张来斌 梁伟 《石油机械》 北大核心 2011年第2期12-14,26,共4页
根据莱特希尔理论可确定天然气管道泄漏处声源为四极子声源,用声强方程和莱特希尔气动力声方程,推导出天然气管道泄漏喷流噪声强度与喷流速度间的关系式。用Matlab软件对天然气管道泄漏声场进行数值模拟,分析了天然气管道泄漏时的声场... 根据莱特希尔理论可确定天然气管道泄漏处声源为四极子声源,用声强方程和莱特希尔气动力声方程,推导出天然气管道泄漏喷流噪声强度与喷流速度间的关系式。用Matlab软件对天然气管道泄漏声场进行数值模拟,分析了天然气管道泄漏时的声场分布及声压级。结果表明,管道内声波形成驻波且整体声压都很大,管道外为四极子声源所产生的声场,声波的辐射和衰减较快;随着泄漏孔直径D和管内运行压力p0的增大,声场声压p和声压级SPL也增大。该项研究为天然气管道泄漏的进一步研究提供了理论基础。 展开更多
关键词 天然气 管道泄漏 气体喷流 泄漏声场 声压级
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基于改进深度神经网络的阀门故障诊断研究 被引量:3
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作者 章修龙 刘贵杰 宁东红 《机电工程》 CAS 北大核心 2022年第10期1356-1364,1373,共10页
在处理含有复杂的噪声成分水声信号时,采用传统的信号处理方法存在一定的困难,并影响水下采油树阀门泄漏故障诊断精度,针对这一问题,提出了一种基于改进的深度神经网络(DNN)的非接触式阀门故障诊断方法。首先,基于阀门泄漏理论,在COMSO... 在处理含有复杂的噪声成分水声信号时,采用传统的信号处理方法存在一定的困难,并影响水下采油树阀门泄漏故障诊断精度,针对这一问题,提出了一种基于改进的深度神经网络(DNN)的非接触式阀门故障诊断方法。首先,基于阀门泄漏理论,在COMSOL仿真环境下,结合轴对称自由射流模型、四极子声源远场声压求解算法,建立了阀门泄漏射流声场模型;然后,基于降噪的基本理论,建立了DNN降噪基本模型,将时频域信号输入到构造好的DNN模型中进行了降噪处理,以最小化信号中的噪声成分;最后,利用经过降噪处理后的水声信号,将其输入构建好的卷积神经网络中,实现了故障诊断目的;设计并进行了水声实验,以验证基于改进的深度神经网络(DNN)的故障诊断方法的有效性。研究结果表明:经过DNN处理后的水声信号,其噪声成分明显降低,其归一化均方误差值由0.4992最低降至0.0110,降幅达97.80%;经过DNN处理后的信号,其故障诊断准确率也达到了98.89%,证明了该方法能有效地诊断阀门的泄漏故障。 展开更多
关键词 深度神经网络 水下采油树阀门 降噪模型 阀门泄漏射流声场模型 阀门泄漏模拟声学实验 故障诊断精度
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Experimental Investigation of Effects of Suction-Side Squealer Tip Geometry on the Flow Field in a Large-scale Axial Compressor using SPIV 被引量:5
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作者 MA Hongwei WEI Wei +1 位作者 WANG Lixiang TIAN Yangtao 《Journal of Thermal Science》 SCIE EI CAS CSCD 2015年第4期303-312,共10页
It is well known that the non-uniform tip geometry is a promising passive flow control technique in turbomachinery.However,detailed investigation of its effects on the unsteady flow field of turbomachinery is rare in ... It is well known that the non-uniform tip geometry is a promising passive flow control technique in turbomachinery.However,detailed investigation of its effects on the unsteady flow field of turbomachinery is rare in the existiug hteratures.This paper presents an experimental investigation of effects of suction side squealer tip configuration on both the steady and unsteady flow field of an isolated compressor rotor.The flow field at 10%chord downstream from the trailing edge was measured using a mini five-hole probe.Meanwhile,the unsteady flow field inside the passage was investigated using stereo particle image velocimetry(SPIV).The steady results show that the SSQ tip configuration exerts positive effect on the static pressure rise performance of this compressor,and the radial equilibrium at the rotor outlet is obviously rearranged.The SSQ tip configuration would create a stronger tip leakage vortex at the formation phase,and it experiences a faster dissipation process around the rear chord.Also,the splitting process of the tip leakage vortex is severer,which is the main cause of the relatively higher probability of the presence of the streamwise reverse flow.The quantitatively analysis of the tip leakage vortex indicates that the velocity loss inside the blockage region is direct response of the evolutionary procedure of the tip leakage vortex.It keeps increasing until the end of the splitting process.Although the blockage coefficient grows sustainably,the velocity loss will reduce once the turbulent mixing procedure is dominant. 展开更多
关键词 tip leakage vortex suction side squealer axial compressor SPIV instantaneous flow field
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