TA105 :
Thesis > Central Library of Shahrood University > Civil & Architectural Engineering > MSc > 2012
Authors:
Abstarct: Rivers and surface water are two major media to release pollutants into the environment
and consequently to the human food chain. Rivers receive wastewaters from human
activities, and due to advection - diffusion are capable of dilute the pollutants and
reduce the concentration of contaminants. This property, known as self attenuation,
enables the release of the contaminated wastewaters into the rivers while the average
water quality in the river remains acceptable for various purposes. The dilution process
takes a minimum distance which depends on the contaminant concentration and
entrance position as well as, hydraulic conditions such as velocity and angle of attacks.
Reduction of this length is of engineering interest since the region of high concentration
pollution is confined. The most preferred method to enhance the mixing process is
elevation of turbulence in the flow. One of the natural techniques to do so is sudden
expansion which accelerates the diffusion process. In this study, the effect of different
entry points of pollutant , expansion ratios and flow rates was studied through a two
dimensional numerical model in which the distribution of pollution in an expansion was
programmed in FORTRAN and MATLAB. The results showed that a sudden expansion
with a ratio in the range of 0.1 to 0.2 is more efficient.
Keywords:
#Advection - Diffusion Equation #Distribution of pollution #Finite Volume Link
Keeping place: Central Library of Shahrood University
Visitor:
Keeping place: Central Library of Shahrood University
Visitor: