Advanced physics

Problem 3.5: Brownian vs Shear induced coagulation: An aerosol is flowing through a hot tubular pipe undergoing pure monodisperse coagulation at 400 K. The residence time of the particles is about 1 min (dp,= 5 um; No= 107 #/cm3). If G = 10 1/s (typical value for the velocity gradient across a gaseous flow with Re = 5'000-10'000), then: a) Calculate the final particle size and number concentration of the aerosol assuming that only shear induced coagulation is of significance. b) At these conditions, Brownian coagulation can take place simultaneously with shear-induced coagulation. Quantify the impact of Brownian coagulation to the total coagulation rate