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Algorithms IV · software · air pollution effects DISPER: 16 air quality management 17 air quality guidelines 18 outdoor air pollution 19 air pollution cause 20 environmental science 21 environmental monitoring 22 environmental impact assessment 23 indoor air quality 24 environmental assesment 25 air monitoring 26 modelling emissions 27 software · pollution 28 environmental engineering 29 atmospheric pollution 30 air pollution 31 environmental maps
Unstable or Neutral  Crossover Between Momentum and Buoyancy For cases with stack gas temperature greater than or equal to ambient temperature, it must be determined whether the plume rise is dominated by momentum or buoyancy. The crossover temperature difference, (DT)_{c}, is determined as follows: for F_{b} < 55, (DT)_{c}=0.0297 T_{s}(v_{s}/d_{s}^{2})^{1/3} (9) and for F_{b} >= 55, (DT)_{c}=0.00575 T_{s}(v_{s}^{2}/d_{s})^{1/3} (10) If DT, exceeds or equals (DT)_{c}, plume rise is assumed to be buoyancy dominated, otherwise plume rise is assumed to be momentum dominated. Unstable or Neutral  Buoyancy Rise For situations where DT exceeds (DT)_{c} as determined above, buoyancy is assumed to dominate. The distance to final rise, x_{f}, is assumed to be 3.5x^{*}, where x^{*} is the distance at which atmospheric turbulence begins to dominate entrainment. The value of x_{f} is calculated as follows: for F_{b} < 55: x_{f}=49F_{b}^{5/8} (11) and for F_{b} >= 55: x_{f}=119F_{b}^{2/5} (12) The final effective plume height, h_{e} (m), is determined as for F_{b} < 55: h_{e}=h_{s}+(21.425 F_{b}^{3/4}/u_{s}) (13) and for F_{b} = 55: h_{e}=h_{s}+(38.71 F_{b}^{3/5}/u_{s}) (14) Unstable or Neutral  Momentum Rise For situations where the stack gas temperature is less than or equal to the ambient air temperature, the assumption is made that the plume rise is dominated by momentum. If DT is less than (DT)_{c}, the assumption is also made that the plume rise is dominated by momentum. The plume height is calculated as: h_{e}=h_{s}+3d_{s}(v_{s}/u_{s}) (15) Briggs suggests that this equation is most applicable when v_{s}/u_{s} is greater than 4.
air pollution effects Air pollution effects: At the present time, numerous universities and study centers use this program for teaching and education. The vehicle emission modeling can be realized with this software.
