Cross winding

Hughes, T. J.R. and Brooks, A.N., 1979, A multidimensional upwind scheme with no cross-wind diffusion. In Hughes, I . J. R. (ed.), Finite Element Methods for Convection Dominated Flows, AMD Vol. 34, ASME, New York. 

In agricultural spraying, one of the biggest concerns is the drifting of small droplets. Drifting sprays not only lead to waste and environment problems, but also could endanger other nearby crops. Droplets smaller than 150 p.m can be easily blown away from the intended target area by a cross wind. A typical herbicide atomizer produces a spray with 15—20% of the Hquid volume contained in droplets less than 150 p.m. Atomizer improvements must be made so that the spray contains a narrow droplet size distribution with Hquid volume less than 5% contributed by the smaller droplets. 

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 ... 

To apply Equation (3), it is necessary to determine the diffusion coefficients Oy and o. The diffusion coefficients can be related to the deviation in the wind direction, given by o, in the azimuth angle (azimuth refers to the lateral or cross-wind direction), and o in the deviation angle (deviation refers to... 

Excessive flattening or crushing. Heavy overload, loose winding on drum, or cross winding. Too infrequent cutoffs on working end of cable-tool lines. Improper cutoff and moving program for cable-tool lines. 

Simulation of a fire resulting from a transport accident in a cross wind. The flame is visualized in yellow/red, while soot clouds are represented in black. (From Tieszen, S., private communication.)... 

The layout of a field study site needs to be established based on the study objectives. Typically, several lines of sample will be laid out in the downwind direction from the application area, perpendicular to the sprayer travel direction assuming a cross-wind normal to the application direction. Three or more parallel lines will provide useful information on spray deposition in the sampling area. If wind directions may be variable, these lines can be set up in various directions radiating outwards from the application area. 

Consider the following situation. Suppose a cross wind of 10 miles/hour is blowing across a tennis court. If a tennis ball is moving perpendicular to the direction the wind is blowing, the ball will follow... 

The main access and egress to a facility preferably should be from the upwind side, with secondary points at cross wind locations. These locations should also be at a relatively higher elevations that the process areas so that possible spillages will not hinder supplemental emergency aid measures from outside the facility. As a minimum two access point should be provided to each facility. 

Oncoming or cross wind effects may reduce the performance of water monitors. When winds of 8 km/hr (5 mph) are present they may reduce the range of water spray by as much as 50%. Consideration should be given to the placement of monitors when the normal wind speed is such to cause performance effects. 

Typical Horizontal Eddy Diffusivities and Cross Wind Standard Deviations... 

Finally, in the case of an infinite, cross wind line source, Eq. (9.39 can be integrated over y from — to + > to give... 

Brzustowski, T.A., Gollahalli, S.R., Gupta, M.P., Kaptein, M. and Sullivan, H.E. 1975a. The Turbulent Piydrogen Diffusion Elame in a Cross Wind. Combustion Science and Technology, (11). 

Thus, the effect of the overspun characteristic is to cause the bullet to drift bodily to the right, away from its original line. If there is a strong cross wind, the bullet will be displaced in the direction of the air flow... 

At short ranges, the effect of a cross wind is about the same in both cases — but... 

Cross Wind and Internal Flow Characteristics of Dry Cooling Towers Russell, C. M. B. McChesney, H. R. Holder, D. W. Jones, T. V., Verlinden, M. 

The authors in association with Oxford University, undertook research, to determine how the arrangement of heat exchanger bundles at the base of a tower affects the tower s internal flow and its sensitivity to cross winds. To learn more about these effects, experiments were conducted with model towers in which heat exchanger bundles were represented by gauze screens. Two types of tests were conducted The first study involved a tower flow in the absence of cross winds which was made at high Reynolds numbers. The second was a study of cross-wind effects made at much reduced Reynolds numbers in a 4m by 2m wind tunnel. 8 refs, cited. 

The author notes that the performance of unit sprays can be expressed in the coefficient of performance per unit temperature difference of water to that of the wet bulb. For large unit sprays, cross wind is important to the performance because the local humidity depends on... 

The layout of the Dunphy experiments is shown in Figure L The experiment consisted of a single swath cross-wind application with various sampling and measuring devices deployed from the swath line to 3600 m downwind. 

Figure 2.7 Low obstacles aligned in rows with angled cross wind (e.g. main and side streets in urban areas). Note that if II/d < 10 a street canyon vortex forms, the wind is deflected along the main street and typically increases with x (complicated by effects of gap between adjacent obstacles e.g. side streets).

Appendix A dispersion from a steady source between elongated obstacles with cross wind (e.g. street canyon)... 

T urbulent diffusion Flames in cross-wind Fuel propane... 

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