Diffraction analysis by gap type breakwater using polynomial approximation for fresnel integrals

Abstract

New solutions for approximation have been proposed to investigate the water wave diffraction, since the wide use of Penny and Price's (1944, 1952) solution of Fresnel integrals. However, there are some difficulties that occur when using the Fresnel integral to solve the diffraction problems at the fields, such as that it requires a long CPU time to obtain the solution. The Polynomial approximation solution has great advantages for both the CPU time in computation and simplified boundary conditions. Numerical simulations based on the Polynomial approximation solution have been implemented to obtain the results in the water wave diffraction problem by both systems of the gap type breakwater for various wave incidences. Then, comparisons on the CPU time and the accuracy of the present solution have been made with those obtained by the Fresnel integral solution. The results of the present study show that the Polynomial approximation solution yields excellent accuracy and agreements with the results obtained by the Fresnel integral, and reduces CPU time by 73.6% for gap type breakwater. Therefore the Polynomial approximation approach may be efficiently used to predict wave fields in shadow region of breakwater in many practical situations. © EuroJournals Publishing, Inc. 2009.