Calibration and Measurement In Turbulence Research by the Hot-Wire Method
Abstract
The calibration and method of making turbulence measurements by means of the hot wire method are described. Methods are given by which the amplitude fluctuations of the wire constants can be determined by simple measurements, as well as the control and compensation of the thermal lag (time constant). King's formula is used for the transformation of the heat loss of a hot wire. Compensation of the thermal lag was accomplished by means of a modified Dryden amplifier and a transformer. The new turbulence measuring apparatus is accurate to within 3 to 4 percent of the measured value. The greatest part of this error is given by the amplifier and the thermal voltmeter, while the direct current part is essentially smaller.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1947
- Accession Number
- ADA801470
Entities
People
- Laszlo Kovasznay
Organizations
- National Advisory Committee for Aeronautics