- Author
-
Motevalli, V.
|
Marks, C. H.
|
McCaffrey, B. J.
- Title
- Measurement of Velocity and Temperature Profiles in Low-Speed, Turbulent Non-Isothermal Flows.
- Coporate
- Maryland Univ., College Park
Maryland Univ., Catonsville
- Sponsor
- National Bureau of Standards, Gaithersburg, MD
- Report
-
NBS GCR 87-535,
November 1987,
21 p.
- Distribution
- Available from National Technical Information Service
- Keywords
-
ceilings
|
probes
|
temperature profiles
|
thermocouples
|
turbulent flow
|
velocity distribution
- Identifiers
- measurements
- Abstract
- A probe has been developed utilizing thermocouples as the sensors which, together with associated data-reduction and processing equipment, makes it possible to measure velocity and temperature profiles in low-speed, turbulent, non-isothermal flows. The technique presented ere might be well suited for transient processes where simulataneous measurements are required in multiple locations. This probe was devised in order to measure the velocity and temperature profiles in the jet formed under a ceiling to measure the velocity and temperature profiles in the jet formed under a ceiling when a buoyant plume from a fire impinges on the ceiling. The probe and the technique used in this work is based on the earlier concept proposed by G. Cox in which the temperature-time records from a pair of thermocouples, one downstream of the other, are cross correlated to determine the flow velocity. Preliminary data has been collected for the velocity and temperature profiles in ceiling jet for small fires. The velocity measurements have undergone extensive calibration tests to determine the degree of confidence in these measurements, calibration results are also included here. This work shows that the technique presented is quite reliable and can predict the mean velocity of turbulent, low-speed, non-isothermal flows within 5% confidence while producing simultaneous temperature measurements.