CAJ | 학술논문

将临近点回归方法与自适应阈值法相结合,对油气水三相流段塞流进行了不稳定周期轨道探寻分析,发现乳状段塞流比水包油段塞流的低阶不稳定周期轨道周期更长.水包油段塞流的低阶轨道由内部小循环到外部大循环的嵌套结构组成,乳状段塞流的低阶轨道则由两个平滑的大循环嵌套而成.结合时频域分析,发现水包油段塞流的能量分布弥散、频谱范围较宽且频率成分复杂,而乳状段塞流的能量分布较集中、高频成分较少,证实水包油段塞流比乳状段塞流流动机理更为复杂,且时频域分布与低阶不稳定周期轨道结构相对应.
장림근점회귀방법여자괄응역치법상결합,대유기수삼상류단새류진행료불은정주기궤도탐심분석,발현유상단새류비수포유단새류적저계불은정주기궤도주기경장.수포유단새류적저계궤도유내부소순배도외부대순배적감투결구조성,유상단새류적저계궤도칙유량개평활적대순배감투이성.결합시빈역분석,발현수포유단새류적능량분포미산、빈보범위교관차빈솔성분복잡,이유상단새류적능량분포교집중、고빈성분교소,증실수포유단새류비유상단새류류동궤리경위복잡,차시빈역분포여저계불은정주기궤도결구상대응.
@@@@We use the close return method combined with adaptive threshold selection to detect the unstable periodic orbits from the signals measured from experimental oil-gas-water three-phase slug flows, and find that the period of the emulsion type slug flow is longer than that of oil in water type slug flow. Especially, the orbit of oil in water type slug flow is basically composed of one big loop and one small loop, and the emulsion type slug flow orbit is composed of two big smooth loops. In addition, we employ the method of adaptive optimal kernel time-frequency representation to investigate the flow behaviors of two typical oil-gas-water three-phase slug flows and indicate that the energy of the oil in water slug flow exhibits a dispersed distribution and its frequency spectrum consists of various components distributes in a wide range. In contrast, the energy of emulsion type slug flow is distributed in a rather concentrated region and the high frequency component in its frequency spectrum is much less than that of the oil in water slug flow. These results are well consistent with the detected structure of unstable periodic orbit, further suggesting that the fluid mechanism underlying oil in water type slug flow is more complicated than that of the emulsion type slug flow.