Bull. Spec. CORESTA Congress, Brighton, 1998, p. 158, ST09

Numerical simulation and experiment study of dynamic flow inside of a cigarette filter

Philip Morris USA, Research Center, Richmond, VA, USA
An understanding of the behavior of smoke stream within a cigarette filter is very important to control the pressure drop and the filtration efficiency in new filter design. The purpose of this study is to investigate the smoke flow pattern for various filter configurations by using the numerical simulations technique. The modified Darcy and the Navier-Stokes equations are solved by a finite different volume method. Calculations of smoke velocity components, and filter pressure drop are performed to predict the smoke flow pattern with the various filter configurations and compared to the observed experiment. The calculated results show that the filter design configuration plays important role in the filter pressure drop and smoke flow pattern. Simulation results also support to develop the mass transfer filter model. This model is proposed to account for the effect of the mass transfer from smoke stream to the filter material based on the approach first order surface kinetic. Aerosol deposition efficiency inside the cigarette filter can be expressed as the integral closed form by using the Laplace transform technique. The numerical calculations indicate that the filtration efficiency depends on the mass transfer coefficient, the filter and flow characteristics. The effect of these parameters are also discussed.