DOI: 10.1615/ICHMT.2009.TurbulHeatMassTransf
ISBN Print: 978-1-56700-262-1
ISSN: 2377-2816
Relationship between gas density and column mode in jet diffusion process
ABSTRAKT
This experimental study aims at investigating the relationship between gas density and column mode in jets diffusion process. Carbon dioxide, helium and air were separately discharged upward from a convergent round nozzle into still air. The velocity fluctuation measurements were carried out in order to investigate the preferred frequency in the potential core and the diffusion structure of the buoyant jet. The influence of the density ratio ρ/ρAir to the preferred frequency was examined. The velocity fluctuation in the potential core was measured by using a hot-wire. The jet diffusion was made visible by using the planar Nd:YAG laser and CCD camera. The range of the Reynolds number is Re = 1×103 - 10×103. It can be observed that the distance until growing up to the vortex ring goes away from the nozzle as increasing the density ratio. The Strohal number doesn't depend on Reynolds number and keep an almost constant value.