{"title":"Non-Stationary Helical 3D Rivulet-Flows of Viscous-Plastic Incompressible Non-Newtonian Fluid","authors":"S. V. Ershkov, E. S. Baranovskii, A. V. Yudin","doi":"10.1002/mma.70747","DOIUrl":null,"url":null,"abstract":"<div>\n \n <p>The novel case of nonstationary flows of <i>helical type</i> governed by gravity-driven viscous-plastic flow dynamics derived for incompressible non-Newtonian fluid is investigated here analytically in case of given (constant) value of <i>Bernoulli</i>-function. In such types of flow, the velocity is linearly and spatially dependent on curl field. Conditions for the existence of the exact solution for the aforementioned type of flows are obtained. Equations of momentum, continuity, and that one for the components of stress tensor are studied. The spatial and time-dependent structure of pressure field of the fluid flow should be determined via constant <i>Bernoulli</i>-function if components of the velocity of the flow are already obtained. It is remarkable that the case of non-stationary <i>helical</i> or <i>Beltrami</i> flow for incompressible gravity-driven viscous-plastic flow governed by three-dimensional equations has been investigated for the first time to the best of our knowledge.</p>\n <p><b>MSC Classification:</b> 35Q35, 76D17</p>\n </div>","PeriodicalId":49865,"journal":{"name":"Mathematical Methods in the Applied Sciences","volume":"49 13","pages":"14382-14392"},"PeriodicalIF":2.0000,"publicationDate":"2026-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Mathematical Methods in the Applied Sciences","FirstCategoryId":"100","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1002/mma.70747","RegionNum":3,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2026/5/13 0:00:00","PubModel":"Epub","JCR":"Q1","JCRName":"MATHEMATICS, APPLIED","Score":null,"Total":0}
引用次数: 0
Abstract
The novel case of nonstationary flows of helical type governed by gravity-driven viscous-plastic flow dynamics derived for incompressible non-Newtonian fluid is investigated here analytically in case of given (constant) value of Bernoulli-function. In such types of flow, the velocity is linearly and spatially dependent on curl field. Conditions for the existence of the exact solution for the aforementioned type of flows are obtained. Equations of momentum, continuity, and that one for the components of stress tensor are studied. The spatial and time-dependent structure of pressure field of the fluid flow should be determined via constant Bernoulli-function if components of the velocity of the flow are already obtained. It is remarkable that the case of non-stationary helical or Beltrami flow for incompressible gravity-driven viscous-plastic flow governed by three-dimensional equations has been investigated for the first time to the best of our knowledge.
期刊介绍:
Mathematical Methods in the Applied Sciences publishes papers dealing with new mathematical methods for the consideration of linear and non-linear, direct and inverse problems for physical relevant processes over time- and space- varying media under certain initial, boundary, transition conditions etc. Papers dealing with biomathematical content, population dynamics and network problems are most welcome.
Mathematical Methods in the Applied Sciences is an interdisciplinary journal: therefore, all manuscripts must be written to be accessible to a broad scientific but mathematically advanced audience. All papers must contain carefully written introduction and conclusion sections, which should include a clear exposition of the underlying scientific problem, a summary of the mathematical results and the tools used in deriving the results. Furthermore, the scientific importance of the manuscript and its conclusions should be made clear. Papers dealing with numerical processes or which contain only the application of well established methods will not be accepted.
Because of the broad scope of the journal, authors should minimize the use of technical jargon from their subfield in order to increase the accessibility of their paper and appeal to a wider readership. If technical terms are necessary, authors should define them clearly so that the main ideas are understandable also to readers not working in the same subfield.