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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unacceptable accuracy and reliability. Thus, the data set resulting from the

experimental investigation was incomplete.

In addition to the absence of dimensional data, other drawbacks existed.

The instability of the flow in the vertical and horizontal directions limited

the growth time to 3 minutes. Furthermore, no mixing mechanism was

present to make the fog uniform with respect to temperature and liquid water

content. Also, no reported device within the pressure cooker secured that

steam production was at a constant level. Therefore, these shortcomings will

limit the usefulness of the data set in this investigation.

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Kowa (1981)

The experimental apparatus included a vertical wind tunnel that was

placed in the refrigerated room. Cold air from the refrigerated room, then,

entered into the fog preparation chamber through an opening located on the

upper corner and mixed with steam laden air that passed through a tube

ending at the cold air entrance. The materials used to build the fog

preparation chamber and most of the other tunnel sections consist of clear

acrylic sheets and aluminum corner brackets. Three shelves divide the

chamber into four sections so that the cold air flows over the entire length of

each shelf before flowing over the bottom.

A pressure cooker producing the steam laden air contained a heating coil

that evenly heats the water. A temperature controner kept the water

temperature at 82.20C as an air bubbler below the water heater forced

compressed air through the water. This arrangement allowed the

investigator to control the steam injection rate in the fog preparation

chamber through adjustment of compressed air flow rate. The resultant

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