Low Reynolds number drag and particle collision efficiency of a cylindrical fiber within a parallel array

• Accurate flow field calculations for Re≤20 and rel. fiber spacings 2≤s/dF≤20.
• Novel fit function to numerical data for fiber drag vs. inter-fiber spacing and Re.
• Modified Stokes number to account for inter-fiber spacing and Re.
• Novel fit function for the collision efficiency due to inertia and interception.

Accurate numerical methods were used for a systematic study of the drag coefficient and the particle collision efficiency of cylindrical filter fibers over a wide range of non-zero Reynolds numbers Re and inter-fiber distances s/dF of practical importance to gas filtration applications.On the basis of the numerical flow field data, a novel fit function was derived for the fiber drag coefficient cD as a function of s/dF and Re   for the parameter range 2≤s/dF≤202≤s/dF≤20 and Re≤20Re≤20.In the second part of the paper CFD and Miyagi-type flow fields were used to calculate the collision efficiency   of spherical, non-diffusive particles for Stokes numbers of 0≤St≤1030≤St≤103 and interception parameters of 0.005≤R≤0.50.005≤R≤0.5. From these numerical data, novel fit functions were derived for the collision efficiency by interception only, and for the combined efficiency by inertia and interception. The effects of fiber spacing s/dF and Re on particle inertia are accounted for by a modified Stokes number.