General description: Two simple, unconfined turbulent jet flames in low-velocity coflow were measured. Nozzles were constructed from 1/4-inch and 3/8-inch straight tubing with squared-off ends. These flames are designated chnA and chnB, with "chn" referring to the fuel mixture of carbon monoxide, hydrogen, and nitrogen. Tubing length is sufficient to make the assumption of fully developed turbulent pipe flow appropriate. The squared-off nozzles provide some stabilization of the flames, which are fully connected. There is no indication of lift off or localized extinction in either flame.

Fuel composition: 40% CO, 30% H₂, 30% N₂

Stoichiometric mixture fraction: F_stoic = 0.295

Flame length: L_stoic ~ 47d

Reynolds number: 16,700 (same for both flames)

Flame chnA: Nozzle inner diameter, d = 4.58 mm; Outer diameter = 6.34 mm; U_jet=76 m/s

Flame chnB: Nozzle inner diameter, d = 7.72 mm; Outer diameter = 9.46 mm; U_jet=45 m/s

Coflow velocity: 0.75 m/s

Scalar Measurements: Simultaneous Raman/Rayleigh/LIF measurements of T, N₂, O₂, CO₂, H₂O, H₂, CO, OH, and NO were obtained with a spatial resolution of 0.75 mm. Results include axial profiles (x/d = 20, 25, 30, ... , 75) and radial profiles (x/d = 20, 30, 40, 50, 60) of mean and rms values, conditional statistics, and single-shot data for each flame. Typically, 800-1000 samples were acquired at each location.

Velocity Measurements: Three-component LDV measurements were conducted by Matthias Flury at ETH Zurich at locations in the flames corresponding to the scalar measurements and at additional locations closer to the nozzle. Data files include axial profiles and radial profiles at x/d=0, 10, 20, 30, 40, 50, 60.

Primary Contact: Robert Barlow (barlow@sandia.gov)

Acknowledgment: Support for the scalar measurements at Sandia was provided by the US Department of Energy, Office of Basic Energy Sciences, Division of Chemical Sciences.

References

Barlow, R. S., Fiechtner, G. J., Carter, C. D., Chen, J.-Y., "Experiments on the Scalar Structure of Turbulent CO/H₂/N₂ Jet Flames," Combust. and Flame 120:549-569 (2000).

Flury, M., "Experimentelle Analyse der Mischungstruktur in turbulenten nicht vorgemischten Flammen," Ph.D. Thesis, ETH Zurich (1998).

Data Archive SANDchn
Release 1.1 -- 15-Jan-03