The Blasius function in the complex plane

被引:58
作者
Boyd, JP
机构
[1] Univ Michigan, Dept Atmospher Ocean & Space Sci, Ann Arbor, MI 48109 USA
[2] Univ Michigan, Sci Computat Lab, Ann Arbor, MI 48109 USA
基金
美国国家科学基金会;
关键词
D O I
10.1080/10586458.1999.10504626
中图分类号
O1 [数学];
学科分类号
0701 [数学]; 070101 [基础数学];
摘要
The Blasius function, denoted by f, is the solution to a simple nonlinear boundary layer problem, a third order ordinary differential equation on x is an element of [0, infinity]. In this work, we calculate several numerical constants, such as the second derivative of f at the origin and the two parameters of the linear asymptotic approximation to f, to at least eleven digits. Although the Blasius function is unbounded, we nevertheless derive an expansion in rational Chebyshev functions TLj which converges exponentially fast with the truncation, and tabulate enough coefficients to compute f and its derivatives to about nine decimal places for all positive real x. The power series of f has a finite radius of convergence, but the Euler-accelerated expansion is apparently convergent for all real x. We show that the singularities, which are first order poles to lowest order, have an infinite series of cosine-of-a-logarithm corrections. Lastly, we chart the behavior of f in the complex plane and conjecture that all singularities lie within three narrow sectors.
引用
收藏
页码:381 / 394
页数:14
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