Combustion dynamics linked to flame behaviour in a partially premixed swirled industrial burner

Experimental analysis of thermo-acoustic instabilities in a generic gas turbine combustor by phase-correlated PIV, chemiluminescence, and laser Raman scattering measurements

“…The main reason for this lies in the complex nature of the interaction between heat release, flow field and acoustic modes of the combustion system. Frequently, minor geometrical modifications of the combustor or small changes in the operating or boundary conditions lead to drastic changes in the stability of the system, such as transition from attached to detached flames or flames with and without precessing vortex cores [Allison 2012, Arndt 2010, Biagioli 2008, Fritsche 2007, Hermeth 2014. In addition, understanding and predicting combustor thermo-acoustic behavior is complicated by significant effects of turbulence-chemistry interaction , Gicqel 2012, Lückerath 2011, Rebosio 2010, and spatially and temporally varying degrees of premixing [Bade 2014, Masri 2015, Stopper 2013.…”

“…single-shot or short-exposure measurements recorded simultaneously with the phase angle of the instability, have been applied to reveal the changes of various quantities during an oscillation cycle. Those measurements include OH* and CH* chemiluminescence to identify heat release variations, OH, CH 2 O and CH PLIF to determine fluctuations in the flame surface density or local Rayleigh index and laser Raman measurements to assess changes in the thermo-chemical state of the flame [Bellows 2007, Biagioli 2008, Giezendanner 2003, Hubschmid 2008, Ishino 2001, Lee 2003, Schildmacher 2006. More recently, high-speed imaging techniques in combination with acoustic pressure tracing have been applied to study thermo-acoustic instabilities in GT-relevant combustors , Caux-Brisebois 2014, Durox 2013, Galley 2011, Gounder 2014, Steinberg 2010, Steinberg 2012, Steinberg 2013, Worth 2012, yielding deeper insight into the feedback mechanisms.…”

Thermoacoustically driven flame motion and heat release variation in a swirl-stabilized gas turbine burner investigated by LIF and chemiluminescence

“…We suppose that this is the main reason for the observed reduced sinusoidal dependence of the LIF intensity on the acoustic phase. In the meanwhile, an alternative to the phase-locking technique is proposed by Güthe and Schuermans (2007) for circumventing this difficulty. They determine the acoustic phase of each laser pulse and group measurements with similar acoustic phases.…”

“…With some time delay the induced variation of the fuel concentration reaches the flame. Biagioli et al (2007) indicate that from the unsteady flame anchoring, sound pressure oscillations also may generate variations of the infinitesimal flame area, i.e. of the angle 0.…”

Large Eddy Simulation of the PVC Behavior in both Non-Reacting and Reacting Flows with Different Reynold Numbers

“…In high swirl flow conditions, the breakdown of vortex induces the formation of central toroidal recirculation zone (CTRZ) inside the combustion chamber [2]. As a result, the heat produced in the combustion recirculate upstream to the exit of the combustor thus improves the stabilization of the premixed-flame [3,4]. Bubble type, axisymmetric with asymmetric tail, spiral, flattened bubble, flattened bubble spiral, double helix and sheared filament type are the basic type of the vortex core breakdown modes according to the studies of Leibovich et al [5] and Faler et al [6].…”