A radiation boundary condition for multi-dimensional flows

✍ Scribed by William H. Raymond; H. L. Kuo

• Book ID: 104575533
• Publisher: John Wiley and Sons
• Year: 1984
• Tongue: English
• Weight: 1010 KB
• Volume: 110
• Category: Article
• ISSN: 0035-9009
• DOI: 10.1002/qj.49711046414

✦ Synopsis

Abstract

A radiation boundary condition designed for use at open or computational boundaries with multidimensional flows is formulated and tested on three two‐dimensional problems. Two of the problems simulate a simple wave propagation and possess analytic solutions so that the effectiveness of the boundary condition can be measured in terms of a r.m.s. error. A more subjective analysis must be used in the final problem, which is the simulation of an atmospheric cold front. The proposed radiation boundary condition utilizes the phase velocity projection in each coordinate direction or equivalently a weighted configuration of the phase velocities. This approach greatly reduces the sensitivity on the spatial derivative normally displayed in the phase velocity calculations. Comparisons are made against the traditionally used Sommerfeld radiation condition and various numerical schemes are tested. For multi‐dimensional flows the proposed radiation boundary condition is found to give significant improvement over the traditional Sommerfeld radiation condition.