ISSN Online: 2377-424X
ISBN Print: 0-89116-130-9
International Heat Transfer Conference 6
PROFILE MEASUREMENTS IN VERTICAL AXISYMMETRIC BUOYANT AIR JETS
Abstract
The behaviour of heated air jets discharged vertically upward from "shaped" circular nozzles into still air has been studied. Tests were undertaken with three nozzles having diameters of 6.4 mm, 9.5 mm and 12.7 mm, the Reynolds numbers involved being between 14 0 0 and 27 00. The temperature of the air leaving the nozzles was approximately 30C above ambient temperature in- the heated jet tests. Distributions of mean velocity, mean temperature and longitudinal turbulence level have been measured. In all cases, measurements were first undertaken with no heating applied and then the measurements were repeated with heating applied. In this way, the effects of the buoyancy forces on the flow characteristics could be determined. In particular, effects of these forces on the form of the velocity and temperature profiles, the rate of spread of the velocity and temperature fields and the variation of conditions along the jet centreline have been studied in detail.