An analytical and experimental study of pressure drop and flow characteristics of a heavy-duty air filter

A mathematical model which simulates the steady, three-dimensional, incompressible turbulent flow in a clean heavy-duty air filter is described. A porous-media-flow submodel based on the extended Darcy's law, as well as experimental techniques of characterizing the porous material, were developed to model the flow through the pleated filter cartridge.;In the numerical model, algebraic grid generation method was used to construct the body-fitted-coordinate grid for the filter housing. The fluid dynamics computation in this study was carried out by using the PHOENICS code, which is based on the finite-volume SIMPLE algorithm for flows in general non-orthogonal coordinate systems. A heavy-duty filter test rig was built, and the overall pressure drop data and static wall pressure distribution were obtained for different flow rates. Compared with the experimental data, the errors of model predictions of overall pressure drop are less than four percent, and the average error of predictions of housing-wall static pressure is from three percent to 10 percent.;Numerical experiments were performed for different positions of the inlet pipe and for a range of housing cylinder and outlet pipe sizes. The filter system was subdivided into a number of smaller regions, so that the individual contribution of each region to the overall pressure loss could be evaluated. It is concluded that at higher flow rates the contribution of the filter-housing geometry to the overall pressure drop is much more than that of the filter cartridge. Simple correlations for estimating pressure drop of the heavy-duty filter system are derived from the results of the numerical model experiments. Finally, the use of computational fluid dynamics as a filter-housing design tool is demonstrated.