WMOD00462

• Contract/Permit #: 87-1999
• Title: Development of Empirical Equations of Ice Crystal Growth Microphysics for Modeling Analysis - Final Report
• Date: 9/1/1988
• Weather Modification - Doc Type: Report

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6.1 mm thick sheet of acrylic containing 225 evenly spaced holes each with a

diameter of 3.56 mm. The total coverage area of the holes was approximately

equal to the cross sectional area of the 5.7 em diameter pipe connecting to the

control valve. The foam rubber filter acted to help equalize the pressure

differential between both sides of the filter and establish a uniform flow at the

top of the chamber. Thus, the suction chamber creates an even flow

throughout the horizontal cross section.

The pipe above the suction chamber guided the fog into the control

valve which was a cylindrical container 14.6 em tan and wide. The cylinder

had three round openings each with a diameter of 5.7 em, with two

positioned at the bottom end and the other located on the side. The two

openings provided entrances for the incoming air: one led from the suction

chamber, and the other directly from the fog chamber through a suction

chamber identical to the one previously described except for the presence of

heating elements that prevented ice buildup. The remaining hole exited the

fog to the vacuum cleaner.

A movable polyethylene plate lying over the valve bottom with the two

holes controlled the flow coming into the control valve. The holes, carefully

placed on the plate, matched the size of the valve opening and covered a total

of exactly one half of the area of the two valve openings irrespective of the

plate adjustments. This plate arrangement kept the total incoming flow and

suction force approximately constant, despite the variation of the flow

through the suspension chamber. Thus, the control valve served to provide

quick changes of the flow rate in the suspension chamber without having to

change the total flow rate of the fog.

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