Winding height

The ETD-34 has an available height inside the bobbin of 6.1 mm. That now leaves 6.1 — 1.434 = 4.67 mm. Therefore each section of the split primary has an available winding height of 2.3 mm only. We should ultimately check that we can accommodate the primary winding we decide on, within this space. 

Trajectory models require spatiaUy and temporaUy resolved wind fields, mixing-height fields, deposition parameters, and data on the spatial distribution of emissions. Lagrangian trajectory models assume that vertical wind shear and horizontal diffusion are negligible. Other limitations of trajectory and Eulerian models have been discussed (30). 

Water flow, gal/min Spray-nozzle pressure, Ih/im Water flow per nozzle, gal/min Effective area, length X width, fd Effective height, ft Wind velocity, ft/min... 

Wind Direction and Speed Wind direc tion is measured at the height at which the pollutant is released, and the mean direction will indicate the direc tion of travel of the pollutants. In meteorology, it is conventional to consider the wind direction as the direction from which the wind blows therefore, a northwest wind will move pollutants to the southeast of the source. 

Parameters Affeeting Gas Dispersion A wide variety of parameters affect the dispersion of gases. These include (1) wind speed, (2) atmospheric stability, (3) local terrain characteristics, (4) height of the release above the ground, (5) release geometry, i.e. from a point, line, or area source, ( momentum of the material released, and (7) buoyancy of the material released. 

The plume model describes continuous release of material. The solution depends on the rate of release, the atmospheric conditions, the height of the release above ground, and the distance from the release. In this case, the wind is moving at a constant speed u in the x direction. The equation for the average concentration for this case is (Crowl and Louvar, 1990, p. 142) ... 

The model requires a specification of the initial cloud volume, the initial plume volume flux, the duration of release, and the initial gas density. Also required is the wind speed at a height of 10 m, the distance downwind, and the ambient gas density. 

In addition to short-term emission estimates, normally for hourly periods, the meteorological data include hourly wind direction, wind speed, and Pasquill stability class. Although of secondary importance, the hourly data also include temperature (only important if buoyant plume rise needs to be calculated from any sources) and mixing height. 

Fig. 17-15. Hodograph showing variation of wind speed and direction with height above ground. SFC = surface wind.

There is normally considerable wind direcHon shear (change of direction) with height, especially near the ground. Although surface friction causes the wind to shift clockwise (veer) with height near the ground, the hori-... 

Wind speed generally increases with height. A number of expressions describe the variation of wind speed in the surface boundary layer. A power law profile has frequently been used in air pollution work ... 

Fig. 19-1. Wind variation with height—measured (solid lines) and one-seventh power law (dashed lines).

Brookhaven Gustiness Classes (Based on Variations of Horizontal Wind Direction over 1 Hr at the Height of Release)... 

As an example of the use of the Gaussian plume equations using the Pasquill-Gifford dispersion parameters, assume that a source releases 0.37 g s of a pollutant at an effective height of 40 m into the atmosphere with the wind blowing at 2 m s . What is the approximate distance of the maximum concentration, and what is the concentration at this point if the atmosphere is appropriately represented by Pasquill stability class B ... 

Measurements of wind, turbulence, and temperature aloft may also be made at various heights on meteorological towers taller than 10 m. WTiere possible, the sensors should be exposed on a boom at a distance from the tower equal to two times the diameter of the tower at that height. 

In this case a-y is 419 m. The peak concentration can be found from the measurements, or from the Gaussian distribution fitted to the data and the peak concentration obtained from the fitted distribution. Provided that the emission rate Q, the height of release H, and the mean wind speed u are known, the standard deviation of the vertical distribution of the pollutant can be approximated from either the peak concentration (actual or fitted) or the cross wind integrated (CWI) concentration from one of the following equations ... 

If the variation in wind speed with height is well approximated with a power law wind profile having an exponent equal to 0.15, how much stronger is the wind at 100 m above ground than at 10 m ... 

The lowering below the stack top of pieces of the plume by the vortices shed downwind of the stack is simulated by using a value h in place of the physical stack height h. This is somewhat less than the physical height when the stack gas exit velocity is less than 1.5 times the wind speed u,... 

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