Abstract

Pollutants' particle transport from point sources through flow channels of municipal rivers have been implicated as a potential spread of the hazardous chemical, biological and physical pollution. The unsteady characteristic of an oscillatory laminar flow of water (Newtonian fluid) with uniform distribution of pollutant particles moving in a river flow channel, has been analytically investigated. The governing equations are composed of the continuity equations and the Navier-stokes equations. The oscillating flow is described by setting one side of boundaries to be a periodic function. The method of analytical expression is presented as an efficient alternative method to the high-performance computing resources of numerical methods whose complexity, availability and requirements delimit their usage. The solution is obtained in the form of a Bessel series. The effects of pollutant particles are described by three parameters: the mass concentration (φ) of the pollutant particles, their frequency (ω) of flow in river channel, and the velocity-lagging time (τ) that measures the rate at which the velocity of the pollutant particles adjusts onto the velocity of the clean water and this depends upon the size of the individual pollutant particles. At different times within the river flow channel the velocity profiles, wall shear stress, and flow rate are graphically represented due to the effects of pollutant parameters (φ) and (τ) and the results obtained are compared with those of the clean water particles.

Keywords: Pollutant, Colloid, Oscillating flow, Mass concentration, Delayed time, Frequency, Number density