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arXiv 1802.07671physics.flu-dyn
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常涡Stokes波:I.数值计算

Stokes waves with constant vorticity: I. numerical computation

Sergey A. Dyachenko, Vera Mikyoung Hur

摘要:

数值计算了常涡量流中受重力作用的周期性行波。Stokes波问题通过保角映射表示为一个非线性伪微分方程,包含一个周期Hilbert变换,并通过Newton-GMRES方法求解。它与快速傅立叶变换一起工作得很好,并且比边界积分方法更有效。结果是在良好的协议,定性和定量,与以前的。对于强正涡量,在有限或无限深,随着陡度的增加,出现悬突剖面,并趋向于触波,其剖面沿波谷线自相交,捕获气泡,随着陡度的进一步增加,数值解变得非物理,并在波速-陡度平面上产生缺口;然后,接触波接管,并且物理解在波速与陡度的平面中跟随,直到它们最终趋向于极端波,其在波峰处表现出尖角。当正涡度强度增加时,悬垂波的高度接近流体圆盘的刚体旋转。

英文摘要:

Periodic traveling waves are numerically computed in a constant vorticity flow subject to the force of gravity. The Stokes wave problem is formulated via a conformal mapping as a nonlinear pseudo-differential equation, involving a periodic Hilbert transform for a strip, and solved by the Newton-GMRES method. It works well with a fast Fourier transform and is more effective than a boundary integral method. The result is in excellent agreement, qualitatively and quantitatively, with earlier ones. For strong positive vorticity, in the finite or infinite depth, overhanging profiles are found as the steepness increases and tend to a touching wave, whose profile self-intersects somewhere along the trough line, trapping an air bubble; the numerical solutions become unphysical as the steepness increases further and make a gap in the wave speed versus steepness plane; a touching wave then takes over and the physical solutions follow in the wave speed versus steepness plane until they ultimately tend to an extreme wave, which exhibits a sharp corner at the crest. Overhanging waves of nearly maximum heights are found to approach rigid body rotation of a fluid disk as the strength of positive vorticity increases.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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