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On the induced airflow and particle resuspension due to a falling disk

Sajadi, B ; Sharif University of Technology | 2013

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  1. Type of Document: Article
  2. DOI: 10.1080/02726351.2012.694133
  3. Publisher: 2013
  4. Abstract:
  5. In this article, the induced airflow and the resultant particles resuspension due to a disk falling freely under the effect of gravity is studied using numerical and experimental approaches. The results showed that an axisymmetric vortex is generated on the disk tip as the disk falls and sheds after impacting the floor. While the effect of this ring vortex on the particles detachment from the floor is small, it has considerable influence on the dispersion of resuspended particles. The simulation results indicated that particles are mainly resuspended from an annular area beneath the disk tip where the generated wall shear is sufficiently high. As particles detachment is mainly controlled by the airflow velocity near the floor, the resuspension rate grows exponentially during the disk falling and drops suddenly as it impacts the floor. The particles deposition rate showed a similar trend, although its peak value occurred slightly later due to particles inertia effects. The effect of main parameters, including particle size, surface roughness, and disk specifications on the particles resuspension rate was also evaluated. The results may find applications for estimating the increase in particles concentration due to human walking, and for developing strategies for minimizing the unfavorable side effects
  6. Keywords:
  7. Falling disk ; Numerical modeling ; Particle image velocimetry (PIV) ; Resuspension ; Dynamic mesh ; Experimental approaches ; Particle image velocimetries ; Particle re suspensions ; Particles concentration ; Particles depositions ; Re-suspension ; Computer simulation ; Floors ; Numerical models ; Surface roughness ; Vortex flow ; Air ; Airflow ; Building ; Dispersion ; Geometry ; Gravity ; Particle resuspension ; Particle size ; Priority journal ; Surface property ; Velocity
  8. Source: Particulate Science and Technology ; Volume 31, Issue 2 , Jun , 2013 , Pages 190-198 ; 02726351 (ISSN)
  9. URL: http://www.tandfonline.com/doi/abs/10.1080/02726351.2012.694133