Laminar Boundary Layers
Laminar Boundary Layers
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层流边界层
DOI：
10.1007/978-3-642-45914-6_3
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发表时间：
1959
期刊：
影响因子：
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通讯作者：
L. Howarth
中科院分区：
文献类型：
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作者：
L. Howarth
1. 介绍。边界层学科正在经历一个快速发展的时期。自1904年PRANDTL 1开始研究以来，它一直是一个活跃的主题，但正如所料，它经历了各种阶段。最初的想法的动力花在了处理边界层的二维方面，这个学科的分支继续稳步发展，直到第二次世界大战。于是，一些努力转向检验可压缩性的影响，这导致了思想的第二次高潮，由此产生了完全能够应用于高速流的原始理论。目前正在进行其发展的其他阶段；一些，如高超声速流动和消散气体中的边界层行为的知识，在本文准备和印刷过程中迅速增长，并在排除的情况下。其他的，例如三维效应的重要性，已经被人们认识了一段时间，并且已经成为广泛研究的主题。乍一看，人们可能会认为，将理论从二维扩展到三维会导致复杂性的增加，而不会产生任何根本性的新思想。这可能在原则上确实是正确的，但重点的变化，例如在讨论分离时需要的变化，可能是深远的，并且是当前许多思想的主题。事实上，这激发了对二维流分离的进一步研究，因为这篇文章最初是写的，并将在适当的地方包含对它的简要参考。最后，对于目前广泛存在的试图确定理论的有效性范围并将其扩展到原来的范围之外的尝试，再怎么重视也不为过。要对一个日益增长的主题作出令人满意的叙述是非常困难的，而一篇短文的限制使这一点更加明显。文章的计划如下。前面的部分将关注二维不可压缩流，随后将讨论将理论扩展到三维。之后，将尝试检验理论获得Navier-Stokes方程近似解的能力，最后将发现可压缩性的影响和边界层激波相互作用的某些方面的讨论。在整个过程中，重点将放在基本思想的发展上，而不是给出更复杂的技术的细节。
1. Introduction. The subject of boundary layers is going through a period of rapid growth. It has always been a lively subject ever since its study was initiated by PRANDTL 1 in 1904 but as is only to be expected, it has gone through a variety of phases. The impetus of the original idea spent itself in dealing with twodimensional aspects of boundary layers and this branch of the subject then continued to grow steadily until the second world war. Some of the effort had then to be turned to examining the effects of compressibility and this led to a second upsurge of thought from which the original theory has emerged fully capable of application to high speed flows. Other phases in its development are now taking place; some, such as knowledge of boundary layer behaviour in hypersonic flow and in dissodating gases have grown rapidly whilst this article has been in course of preparation and printing and are in the circumstances excluded. Others, such as the importance of three-dimensional effects, have been appreciated for some time and have already been the subject of wide-spread investigation. At first sight it might be imagined that the extension of the theory from two to three dimensions would cause an increase in complexity without calling into play any fundamentally new ideas. This may indeed be true in principle but changes of emphasis such as are needed in discussing separation for example, may be far reaching and are the subject of much current thought. Indeed this has stimulated further work on separation in two-dimensional flow since this article was originally written and a brief reference to it will be included at the appropriate place. Finally, too much importance cannot be attached to the attempts at present widespread to determine the ranges of validity of the theory and to extend it beyond its original confines.It is very difficult to give a satisfactory account of a growing subject and the confines of a short article make this doubly apparent. The plan of the article is as follows. The early parts will be concerned with the two-dimensional incompressible flow and these will be followed by a discussion of the extension of the theory to three dimensions. After that there will be an attempt to examine the ability of the theory to obtain approximate solutions of the Navier-Stokes equations and finally there will be found a discussion of the effects of compressibility and some aspects of boundary-layer shock-wave interaction. Throughout, emphasis will be laid on the development of the fundamental ideas rather than on giving details of the more elaborate techniques.