PHYSICAL AND NUMERICAL MODELLING OF THE DYNAMIC BEHAVIOR OF A FLY LINE

✍ Scribed by C. GATTI-BONO; N.C. PERKINS

• Publisher: Elsevier Science
• Year: 2002
• Tongue: English
• Weight: 301 KB
• Volume: 255
• Category: Article
• ISSN: 0022-460X
• DOI: 10.1006/jsvi.2001.4180

✦ Synopsis

The planar equations of motion for a tapered #y line subjected to tension, bending, aerodynamic drag, and weight are derived. The resulting theory describes the large non-linear deformation of the line as it forms a propagating loop during #y casting. A cast is initiated by the motion of the tip of the #y rod that represents the boundary condition at one end of the #y line. At the opposite end, the boundary condition describes the equations of motion of a small attached #y (point mass with air drag). An e$cient numerical algorithm is reviewed that captures the initiation and propagation of a non-linear wave that describes the loop. The algorithm is composed of three major steps. First, the non-linear initial-boundary-value problem is transformed into a two-point boundary-value problem, using "nite di!erencing in time. The resulting non-linear boundary-value problem is linearized and then transformed into an initial-value problem in space. Example results are provided that illustrate how an overhead cast develops from initial conditions describing a perfectly laid out back cast. The numerical solutions are used to explore the in#uence of two sample e!ects in #y casting, namely, the drag created by the attached #y and the shape of the rod tip path.