An integrated experimental-numerical procedure has been developed for fuel-air mixing prediction in a heavy-duty gas turbine burner. Optical measurements of the degree of mixing have been performed in a full-scale test rig operating with cold flow. Experimental data have been utilized to validate a CFD RANS numerical model. In fact, it is recognized that the turbulence behavior of jets in swirling air-flow stream is not accurately described by standard $k-ε$ turbulence models; therefore advanced turbulence models have been assessed by means of experimental data. The degree of mixing between simulated fuel and air streams has been evaluated at the burner exit section by means of a planar Mie scattering technique. The experimental apparatus consists of a pulsed Nd:YAG laser and a high resolution CCD video camera connected to a frame grabber. The acquired instantaneous images have been processed through specific procedures that also take into account the laser beam spatial nonuniformity. A second-order discretization scheme with a RSM turbulence model gives the best accordance with the experimental data. Such CFD model will be part of a more general method addressed to numerical prediction of turbulent combustion flames in LP technology.

1.
Lefebvre, A. H., 1995, “The Role of Fuel Preparation in Low Emission Combustion,” ASME Paper No. 95-GT-465.
2.
Gazzani, F., and Mori, G., 1997, “CFD Modeling of Turbulent Premixed Combustion in a Heavy Duty Gas Turbine,” Fluent Users’ Seminar, Manchester, UK.
3.
Mori, G., Hoffmann, S., and Di Meglio, A., 1997, “Numerical Procedure for Optimization of a Liquid Fuel Premix Burner Injection System,” ILASS Int., Florence.
4.
Hoffmann, S., Judith, H., and Holm, C., 1998, “Further Development of the Siemens LPP Hybrid Burner,” ASME Paper No. 98-GT-552.
5.
Nicol, D., Malte, P. C., Hamer, A. J., Roby, R. J., and Steele, R., 1998, “Development of a Five Step Global Methane Oxidation—NO Formation Mechanism for Lean Premix Gas Turbine Combustion,” ASME Paper No. 98-GT-185.
6.
Rutar, T., Martin, S., Nicol, D. G., Malte, P. C., and Pratt, D. T., 1997, “Effect of Incomplete Premixing on NOx Formation at Temperature and Pressure Condition of LP Combustion Turbine,” ASME Paper No. 97-GT-335.
7.
Dugue´, J., Mbiock, A., and Weber, E. R., 1994, “Mixing Characterization in Semi-industrial Natural Gas Flames Using Planar Mie-Scattering Visualization,” Seventh Int. Symp. on Appl. of Laser Techniques to Fluid Mech., Lisbon.
8.
Eaton
,
A. R.
,
Frey
,
S. F.
,
Cusano
,
D. M.
,
Plesniak
,
M. W.
, and
Sojka
,
P. E.
,
1996
, “
Development of a Full-Field Planar Mie Scattering Technique for Evaluating Swirling Mixers
,”
Exp. Fluids
,
21
, pp.
325
330
.
9.
Coklat, D., 1998, “Advanced Turbulence Modeling,” lecture at “CFD in Combustion Engineering” course, Leeds University, Leeds, UK.
10.
Liever, P. A., Myers, G. D., Hernandez, L., and Griffith, T., 1998, “CFD Assessment of a Wet, Low-NOx Combustion System for a 3 MW-Class Industrial Gas Turbine,” ASME Paper No. 98-GT-292.