COBEM99

SR4 Combustão

Title:

EFFECT OF OSCILLATION FREQUENCY AND AMPLITUDE IN THE SHAPE OF PULSATING PREMIXED FLAMES

Summary :

SUMMARY. THE PULSATING COMBUSTION HAS WON INTEREST IN THE CURRENT RESEARCHES DUE TO THE INDICATIONS THAT ITS APPLICATION IN THE ENERGY GENERATION CAN OFFERS SEVERAL ADVANTAGES, SUCH AS: FUEL ECONOMY, REDUCED POLLUTANTS FORMATION, INCREASES THE RATE OF CONVECTIVE HEAT TRANSFER AND REDUCED INVESTMENT WHEN COMPARED WITH CONVENTIONAL TECHNIQUES. HOWEVER, THE PULSATING COMBUSTION SYSTEMS WHERE THE OWN COMBUSTION PROCESS INDUCES THE ACOUSTIC OSCILLATION, IN GENERAL, THEY ARE OPERATIONALLY UNSTABLE AND ARE NOT VERY ATTRACTIVE FOR INDUSTRIAL APPLICATIONS. THIS WAY, THE FUTURE OF PULSATING FLAMES CAN BE IN PROCESSES WHERE THE OSCILLATION IS INDUCED BY EXTERNAL MEANS, FOR EXAMPLE BY A SPEAKER. THE PRESENT WORK PRESENTS THE EFFECT OF THE AMPLITUDE AND FREQUENCY IN THE FORMAT OF A PRE-MIXED FLAME OF LGP. THE MIXTURE IS EXCITED ACOUSTICALLY BEFORE THE BURNER EXIT, THROUGH A SPEAKER POSITIONED STRATEGICALLY, AND THE FLAME VISUALIZATION WAS MADE BY A CAMERA CCD. THEN, A TOMOGRAPHIC RECONSTRUCTION PROCESS IS APPLIED IN THE OBTAINED IMAGES, WHERE THE INTEGRAL OF THE INVESTMENT OF ABEL IS APPLIED. THE RESULTS SHOW THAT THE AMPLITUDE HAS INFLUENCE IN THE LENGTH OF THE FLAME, FOR LOW FREQUENCIES. BY THE WAY, THE FREQUENCY ALTERS COMPLETELY THE STRUCTURE OF THE RECIRCULATION ZONE AT THE GAS EXIT OF THE BURNER.

Author :

Caldeira Pires, Armando de A.
CARVALHO Jr, JOÃO ANDRADE DE
FERREIRA, DANIEL SILVA
LACAVA, PEDRO TEIXEIRA

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