Combustor performance enhancement through direct shear layer excitation

Journal Article · Mon Oct 01 00:00:00 EDT 1990 · Combustion and Flame; (USA)

DOI:https://doi.org/10.1016/0010-2180(90)90079-7· OSTI ID:6517217

McManus, K R; Vandsbuvger, U; Bowman, C T ^[1]

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1. Stanford Univ., CA (USA). Dept. of Mechanical Engineering

Previous studies of turbulent nonreacting shear flow have shown that flow excitation can provide enhanced entrainment and mixing. In this study, the effects of periodic flow excitation on the performance of a two-dimensional dump combustor were investigated for lean premixed conditions. The flow excitation was in the form of a sinusoidal cross-stream velocity perturbation applied just upstream of the flow separation. The forcing frequencies, chosen such that they corresponded to resonant and off-resonant vortex shedding frequencies indentified in unforced combustion, ranged from 35 to 400 Hz. The effect of forcing on both nonreacting and reacting flowfields was to modulate the formation of vortex structures just downstream of the flow separation. In the nonreacting flowfield, the shear layer spreading rate increased when forcing was applied. In the reacting flow, forcing caused a modulation of the flame structure. Forcing increased the mean CH emission intensity from the flame, which is related to mean volumetric energy release, up to 15%, reduced the rms pressure fluctuation level by up to 30%, and reduced the equivalence ratio at the lean blowoff limit up to 6% NO{sub x} emissions were reduced by up to 20{percent} with forcing.

• OSTI ID: 6517217
• Journal Information: Combustion and Flame; (USA), Journal Name: Combustion and Flame; (USA) Vol. 82:1; ISSN CBFMA; ISSN 0010-2180
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400800* -- Combustion
Pyrolysis
& High-Temperature Chemistry
42 ENGINEERING
420400 -- Engineering-- Heat Transfer & Fluid Flow
421000 -- Engineering-- Combustion Systems
CHALCOGENIDES
CHEMICAL REACTION KINETICS
COHERENT SCATTERING
COMBUSTION KINETICS
COMBUSTORS
DISPERSIONS
EMISSION
FLAME PROPAGATION
FLUID FLOW
KINETICS
MIXTURES
NITROGEN COMPOUNDS
NITROGEN OXIDES
OXIDES
OXYGEN COMPOUNDS
PARAMETRIC ANALYSIS
PERFORMANCE TESTING
PRESSURE GRADIENTS
RAYLEIGH SCATTERING
REACTION KINETICS
SCATTERING
SHEAR
TESTING
TURBULENT FLOW
TWO-DIMENSIONAL CALCULATIONS
VELOCITY