Volume No. 5 Issue No.: 2 Page No.: 330-339 October-December 201

 

POLLUTANT DISPERSION IN THE WAKE OF A HILL : A NUMERICAL ANALYSIS

 

Harishankar Manikantan1 and Pruthviraj U.*2

1. Department of Mechanical Engineering
2. Department of Applied Mechanics and Hydraulics National Institute of Technology Karnataka, Surathkal (INDIA)

 

Received on : June 07, 2010

 

ABSTRACT

 

This paper aims at numerically determining a detailed pattern of the concentration profile due to the exhaust from plumes in the wake region of a hill-like obstruction. The pollutant concentrations at these points are locally very different from expected levels. For simulation and experimental ease, a squared sinusoidal equation is approximated as the hill profile. This may be replicated in a wind tunnel facility for experimental data acquisition. Popular turbulent models are used to simulate the problem in a finite element based solver. The effect of varying pollutant exhaust velocities, plume location and hill slope are investigated. We conclude that the farther away the plume from the hill, lesser is the pollutant trapped in the recirculation zone. Also, a steeper hill is found to give rise to a larger wake and corresponding extent of recirculation. Effect of pollutant density and the recirculation effects on pollutant dispersion in the leeward side of the hill are discussed at length. Such studies are of use in planning and locating exhausts for minimal interference with inhabited zones.

 

Keywords : Pollutant dispersion, Atmospheric boundary layer, Recirculation, Plume location, Numerical simulation, Flow over a hill

 

 

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