Wyngaard [16] suggested a tensor instead of a scalar representation of the eddy diffusivity to improve gray zone simulations using Eddy Viscosity closures.
where [K.sub.c] is the eddy diffusivity coefficient, z is the height, and t is time.
E., 1984: Vertical
eddy diffusivity in the ocean interior.
Kakamari, "Time dependent mathematical model of air pollution due to area source with variable wind velocity and
eddy diffusivity and chemical reaction," vol.
where C(x, y, z) denotes the concentration, [k.sub.x], [k.sub.y], [k.sub.z] are the cartesian components of eddy diffusivity and u, [upsilon], w are the cartesian components of wind speed, where x, y are cartesian horizontal distance and z is the height above ground surface.
However, these solutions are restricted to the specific case in which the source is located at the ground level and/or with restrictions to the wind speed and eddy diffusivity vertical profiles.
There are two approaches such as the
eddy diffusivity model and the surface renewal model which is widely used to model heat transfer at wall boundary (Tricoli, 1999).
Eddy diffusivity [v.sub.E] is equal to eddy viscosity [v.sub.t].
Thus, the Reynolds stress (-[rho][bar.[u'.sub.i][u'.sub.j]]) and the Reynolds heat flux (-[bar.[u'.sub.j][theta]]) are modeled on the basis of the eddy viscosity and
eddy diffusivity models, respectively.
5(b), which show calculated
eddy diffusivity using the QETE model with both types of the surface boundary conditions.
An analytical model using
eddy diffusivity is applied for predicting droplet concentration distribution and liquid film formation in a Venturi scrubber.