Nomenclature A2 = torsional-stability aerodynamic coefficient Cp = specific heat at constant pressure dp = diameter of particle D = stack diameter e = coefficient of restitution / = natural frequency of building g = gravitational acceleration h = source height H = height of structure k = thermal conductivity of fluid or concentration coefficient K = wave number Kc = eddy diffusivity for contaminant KM = eddy diffusivity for momentum L = reference length p = pressure Q = emission rate t = time T = mean temperature AT = temperature difference uf = terminal fall velocity of particle U = mean velocity Vs = exit speed of stack emissions x = longitudinal coordinate y = lateral coordinate z = vertical coodinate Z0 = roughness length a. = wind direction 6 = boundary-layer thickness e = energy dissipation rate per unit of mass f = dimensionless height (z/z0) p = mass density 6 = potential temperature fi = dynamic viscosity v kinematic viscosity X = concentration of contaminant oj = angular velocity ft = angular velocity of coordinate system