VELOCITY MEASUREMENTS IN A VISCOUS FLUID WITH A HOT-WIRE ANEMOMETER,
Abstract
The measurement of small velocities in a highly viscous fluid is impractical if standard static-impact tube methods are employed. Fluid resistance to flow is great and, consequently, measurements with a static-impact system are too time-consuming to be useful. Since a system requiring fluid movement through a constricted passage could not be employed, velocity measurements were made with a hot-wire anemometer. The investigation of the problems involved and the techniques developed in adapting the hot-wire anemometer for these velocity measurements are the subjects of the report. The hotwire sensing element was successfully calibrated by use of a current difference technique. This calibration curve was used to measure seven velocity profiles, and the resulting profiles are thoroughly discussed. The report includes a discussion of the effects of hot-wire sensing element geometry; end conduction heat loss from the hot-wire sensing element; radial temperature gradient at the test section; and the effect of the hot-wire probe on the measurements under certain conditions. Recommendations are made for the design of an improved hot-wire probe and an improved hot-wire sensing element positioning device together with a recommended technique for the extensions of the calibration curve. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 05, 1965
- Accession Number
- AD0623278
Entities
People
- Fred J. Contrata Jr.
Organizations
- Navy Underwater Sound Laboratory