Accession Number : ADP008993

Title :   LDA Measurements of Velocity and Turbulent Transport Processes in a 150 KW Baffle-Stabilized Swirling Flame,

Corporate Author : TECHNICAL UNIV OF LISBON (PORTUGAL)

Personal Author(s) : Durao, D. F. ; Fernandes, E. C. ; Heitor, M. V. ; Moreira, A. L. ; Simoes, J. P.

Report Date : 23 JUL 1992

Pagination or Media Count : 8

Abstract : A laser-Doppler velocimeter has been used to quantify the velocity characteristics of an unconfined recirculating flame with an heat load around 150 kW formed downstream of an annular jet propane gas surrounded by a co-axial swirling air flow, which was set at Re = 58000. The results characterize the aerodynamics of disc-stabilized non-premixed flames within a swirling air flow and include the analysis of the rate of heat transfer in these flames. To achieve these objectives, the laser velocimeter was combined with digitally-compensated fine-wire thermocouples, which have also allowed to quantify the extent of the degree of internal mixing obtained in annular swirling flames. The results were obtained for fuel-lean conditions (AFR = 44.7) and identify an annular swirling flow associated with a double vortical structure established in the wake of the baffle with maximum negative velocities around 0.20 U sub 9 at r/D sub 9 = 0.45 and positive centerline velocities up to +0.1 U sub 9. The diffussion of heat in the radial direction is shown to follow conventional scalar-viscosity concepts, but there are large zones of the reacting shear layer where the results show axial counter-gradient diffusion of heat

Descriptors :   *TURBULENT FLOW, *LASER VELOCIMETERS, DOPPLER SYSTEMS, JET FLOW, ANNULAR BURNERS, EDDIES(FLUID MECHANICS), BAFFLES, HEAT TRANSFER, THERMOCOUPLES, REYNOLDS NUMBER, COAXIAL CONFIGURATIONS, PORTUGAL.

Subject Categories : Fluid Mechanics
      Optical Detection and Detectors

Distribution Statement : APPROVED FOR PUBLIC RELEASE