Numerical dispersion in mildly curved channel using multiquadric radial basis function (MQRBF) method

Abstract

Curvature in a channel affects the flow and dispersion in many ways and lateral variation in the stream wise velocity is one of the key factors for dispersion mechanism in channel flows. This paper attempts to study the dispersion of a solute in a mildly curved channel using multiquadric radial basis function. Combined effect of molecular diffusion and convection is analyzed by solving the non-dimensional convective-diffusion equation for curved channel. The small Peclet number with different curvature ratios has been examined and it is observed that the MQRBF method works well for studying the concentration distribution. It is also found that the accuracy of the solution deteriorates as Peclet number increases. For large Peclet number, convection dominated over the dispersion phenomenon and hence, upwind scheme is required to stable the numerical instability. This is prologue study for a complete numerical model which has no constraints on the curvature ratio and the concentration distribution may analyz...