Accession Number : AD0623278

Title :   VELOCITY MEASUREMENTS IN A VISCOUS FLUID WITH A HOT-WIRE ANEMOMETER,

Corporate Author : NAVY UNDERWATER SOUND LAB NEW LONDON CONN

Personal Author(s) : Contrata,Fred J. ,Jr.

Report Date : 05 OCT 1965

Pagination or Media Count : 41

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)

Descriptors :   (*ANEMOMETERS, VELOCITY), (*FLUID FLOW, MEASUREMENT), VISCOSITY, LAMINAR FLOW, TEST EQUIPMENT, CIRCUITS, HEAT TRANSFER

Distribution Statement : APPROVED FOR PUBLIC RELEASE