A generalized finite spectral method is proposed. The method is of high-order accuracy. To attain high accuracy in time discretization, the fourth-order Adams-Bashforth-Moulton predictor and corrector scheme was used. To avoid numerical oscillations caused by the dispersion term in the KdV equation, two numerical techniques were introduced to improve the numerical stability. The Legendre, Chebyshev and Her-mite polynomials were used as the basis functions. The proposed numerical scheme is validated by applications to the Burgers equation (nonlinear convection- diffusion problem) and KdV equation (single solitary and 2-solitary wave problems), where analytical solutions are available for comparison. Numerical results agree very well with the corresponding analytical solutions in all cases.
The effects of the direction of current on the drag on fish cages are studied in the present paper. The drags on cages of different shapes, including cylindrical, truncated conical, cuboidal and hexagonal, are compared. The drag on the truncated conical net is smaller than that on other shapes of the same area. This net shape with a small apex angle is suggested for the design of fish cages.
