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Module 3: Characteristics of Particles - Aerodynamic Diameter - Practice Problems
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Instructions:
- Work these problems on a sheet of paper and check your answers against those provided below.
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#1 - Calculate the diameter (dpa) of a particle having a Stokes diameter (dps) of 2.0 micrometers and a density of 2.7 gm/cm3.
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Answer: 3.29
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Solution:
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#2
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Calculate the diameter (dpa) of the following
particles.
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The particle in Practice Problem 1 if the Stokes diameter is
doubled.
- The particle in Practice Problem 1 if the particle is twice as dense.
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The particle in Practice Problem 1 if the Stokes diameter is
doubled.
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Answer: i. 6.57
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Solution:
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Calculate the diameter (dpa) using a Stokes diameter of
4 .
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Note that doubling the Stokes diameter doubles the aerodynamic
diameter, dpa.
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Answer: ii. 4.65
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Solution:
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Calculate the diameter (dpa) using a particle density of
5.4 gm/cm3.
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- Both the Stokes diameter and the density of the particle affect the aerodynamic diameter, dpa. However, the Stokes diameter of the particle has a greater effect than its density on the aerodynamic diameter, dpa.