{"title":"扁平通道初始段的层流脉动流","authors":"E. P. Valueva, V. S. Zukin","doi":"10.1134/s0018151x23040168","DOIUrl":null,"url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>A method is proposed for solving the problem of a pulsating quasistationary flow in a channel, based on the use of calculation results for stationary flow. This approach is applicable at low relative oscillation frequencies (for Womersley numbers less than one). The solution to the system of stationary equations of motion and continuity in the initial section of a flat channel was carried out by the finite difference method using an iterative implicit unconditionally stable scheme. The hydrodynamic characteristics of a developing pulsating laminar flow in a flat channel have been studied. The results of calculating the longitudinal velocity component and the Poiseuille and Euler numbers are presented as a function of the relative amplitude of the oscillation of the cross-sectional average velocity <i>A</i> and dimensionless length of the channel. It was found that for <i>A</i> values exceeding unity, the period-averaged coefficients of hydraulic resistance and friction resistance near the inlet to the channel are significantly higher than these values for a stationary flow. It has been shown that in order to achieve a pulsating flow with large amplitudes of oscillations, it is necessary to create a time-average pressure drop approximately three times higher (at <i>A</i> = 5) than for a stationary flow.</p>","PeriodicalId":13163,"journal":{"name":"High Temperature","volume":"13 1","pages":""},"PeriodicalIF":1.0000,"publicationDate":"2024-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Laminar Pulsating Flow at the Initial Segment of a Flat Channel\",\"authors\":\"E. P. Valueva, V. S. Zukin\",\"doi\":\"10.1134/s0018151x23040168\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<h3 data-test=\\\"abstract-sub-heading\\\">Abstract</h3><p>A method is proposed for solving the problem of a pulsating quasistationary flow in a channel, based on the use of calculation results for stationary flow. This approach is applicable at low relative oscillation frequencies (for Womersley numbers less than one). The solution to the system of stationary equations of motion and continuity in the initial section of a flat channel was carried out by the finite difference method using an iterative implicit unconditionally stable scheme. The hydrodynamic characteristics of a developing pulsating laminar flow in a flat channel have been studied. The results of calculating the longitudinal velocity component and the Poiseuille and Euler numbers are presented as a function of the relative amplitude of the oscillation of the cross-sectional average velocity <i>A</i> and dimensionless length of the channel. It was found that for <i>A</i> values exceeding unity, the period-averaged coefficients of hydraulic resistance and friction resistance near the inlet to the channel are significantly higher than these values for a stationary flow. It has been shown that in order to achieve a pulsating flow with large amplitudes of oscillations, it is necessary to create a time-average pressure drop approximately three times higher (at <i>A</i> = 5) than for a stationary flow.</p>\",\"PeriodicalId\":13163,\"journal\":{\"name\":\"High Temperature\",\"volume\":\"13 1\",\"pages\":\"\"},\"PeriodicalIF\":1.0000,\"publicationDate\":\"2024-03-21\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"High Temperature\",\"FirstCategoryId\":\"101\",\"ListUrlMain\":\"https://doi.org/10.1134/s0018151x23040168\",\"RegionNum\":4,\"RegionCategory\":\"物理与天体物理\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q4\",\"JCRName\":\"PHYSICS, APPLIED\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"High Temperature","FirstCategoryId":"101","ListUrlMain":"https://doi.org/10.1134/s0018151x23040168","RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"PHYSICS, APPLIED","Score":null,"Total":0}
引用次数: 0
摘要
摘要 在利用静止流计算结果的基础上，提出了一种解决通道中脉动准静止流问题的方法。这种方法适用于较低的相对振荡频率（沃默斯利数小于 1 时）。采用迭代隐式无条件稳定方案，通过有限差分法求解了平坦水道初始断面的静止运动和连续性方程组。研究了平直水道中发展脉动层流的流体力学特性。纵向速度分量、泊伊数和欧拉数的计算结果是横截面平均速度 A 的相对振幅和通道无量纲长度的函数。研究发现，当 A 值超过 1 时，渠道入口附近的水力阻力和摩擦阻力的周期平均系数明显高于静止流的这些值。研究表明，为了获得振幅较大的脉动水流，必须产生比静止水流高出约三倍（A = 5 时）的时间平均压降。
Laminar Pulsating Flow at the Initial Segment of a Flat Channel
Abstract
A method is proposed for solving the problem of a pulsating quasistationary flow in a channel, based on the use of calculation results for stationary flow. This approach is applicable at low relative oscillation frequencies (for Womersley numbers less than one). The solution to the system of stationary equations of motion and continuity in the initial section of a flat channel was carried out by the finite difference method using an iterative implicit unconditionally stable scheme. The hydrodynamic characteristics of a developing pulsating laminar flow in a flat channel have been studied. The results of calculating the longitudinal velocity component and the Poiseuille and Euler numbers are presented as a function of the relative amplitude of the oscillation of the cross-sectional average velocity A and dimensionless length of the channel. It was found that for A values exceeding unity, the period-averaged coefficients of hydraulic resistance and friction resistance near the inlet to the channel are significantly higher than these values for a stationary flow. It has been shown that in order to achieve a pulsating flow with large amplitudes of oscillations, it is necessary to create a time-average pressure drop approximately three times higher (at A = 5) than for a stationary flow.
期刊介绍：
High Temperature is an international peer reviewed journal that publishes original papers and reviews written by theoretical and experimental researchers. The journal deals with properties and processes in low-temperature plasma; thermophysical properties of substances including pure materials, mixtures and alloys; the properties in the vicinity of the critical point, equations of state; phase equilibrium; heat and mass transfer phenomena, in particular, by forced and free convections; processes of boiling and condensation, radiation, and complex heat transfer; experimental methods and apparatuses; high-temperature facilities for power engineering applications, etc. The journal reflects the current trends in thermophysical research. It presents the results of present-day experimental and theoretical studies in the processes of complex heat transfer, thermal, gas dynamic processes, and processes of heat and mass transfer, as well as the latest advances in the theoretical description of the properties of high-temperature media.
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