INSTRUMENTATION FOR LOKI WIND MEASUREMENTS
Abstract
A balloon-borne hot-wire anemometer program was undertaken to obtain wind information up to altitudes which could account for a significant portion of Loki deviation at burnout. The system comprises a balloon supporting a cable upon which hot-wire anemometers are attached at 75, 175, 300, 600, and 1000 ft. The balloon tethering wire acts as a 6-conductor cable for engineering and reading the hot wire. A data multiplexor samples the 5 information channels with a 1.2-sec scanning cycle for recording with a single-channel Sanborn recorder. A theoretical analysis of the hot-wire anemometer is appended as well as a discussion of errors and an experimental method for determining the time constant. A configuration for a 2-component anamometer was developed which provides stability within 2 mph up to wind speeds of 70 mph. Wind-tunnel tests indicated fluctuations corresponding to a peak lift force about 60% of the drag force at 60 mph. Roughing the surface reduced the fluctuation to 5% of the drag at 60 mph. From the point of view of manufacture and reproducibility- requirements, the desired roughness was induced by an arrangement with slots 1.8 in. wide by 1/6 in. deep and 1/8 in. spacing.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1953
- Accession Number
- AD0014088
Entities
People
- Richard K. Smyth