Plume velocity

A downward flowing exhaust through the grizzly and into the hopper directly counteracts the plume velocity. 

In well-developed fires, the convective heat fraction is typically measured at more than about 65% of the total heat release rate (Heskestad, 2002). This heat is carried away by the plume above the flames. Prediction of plume velocity and temperatures above the flames serve as the basis for convective heat transfer calculations where overhead equipment exists. Widely used fire plume theory assumes a point source origin, and uniformity throughout the plume relative to air density, air entrainment, velocity profile, and buoyancy. 

The entrainment functions in the previous section require estimates of the in-plume velocity scales M. and w Jensen (1981) made an analogy with the atmospheric surface layer in which the velocity and temperature profiles are ... 

The plume velocity is the velocity with which an aerosol is released from an MDI. Generally, the plume velocity from hydrofluoroalkane (HFA) holding MDIs is much lower than that from chlorofluorocarbon (CFG) holding MDIs, but this may depend on the presence of a co-solvent... 

In contrast to DPIs the basic design of MDI hardware is well described in the literature [23, 24]. Most MDIs apparently have a simpler design than DPIs and a key advantage of MDI systems is their low cost per dose. They are portable, convenient and have widespread acceptance by patients and clinicians. Basically they all have the same operational principle and furthermore all MDIs deliver a constant fine particle dose (independent of the flow rate). Whereas they have a relatively low resistance to airflow and this all makes the inhalation instruction less dependent oti the individual type of MDI. The most relevant differences between types are in the actuator design and medicine formulation (solution or suspension), in which the type of propellant and the presence of co-solvents play an important role because of their influence on the (plume) velocity with which the aerosol is released from the actuator and rate of droplet evaporation. 

P. Weibring, M. Andersson, H. Edner, S. Svanberg Remote monitoring of industrial emissions by combination of lidar and plume velocity measurements. Appl. Phys. B 66, 383 (1998)... 

Ulbrecht, J. J. and Baykara, Z. S. (1981) Significance of the Central Plume Velocity for the Correlation of Liquid Phase Mixing in Bubble Columns , Chem. Eng. Comm. 10, 165-168. 

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