• Title/Summary/Keyword: Rijke Burner

Search Result 4, Processing Time 0.021 seconds

Characteristics of thermoacoustic oscillation in ducted flame burner (관형 연소기의 열 음향학적 특성에 관한 실험적 연구)

  • 조상연;이수갑
    • Journal of KSNVE
    • /
    • v.7 no.6
    • /
    • pp.985-991
    • /
    • 1997
  • Combustion instability is a common phenomenon in a ducted flame burner and is known as accompanying low frequency oscillation. This is due to the interaction between unsteady heat release rate and sound pressure field, that is, thermoacoustic feedback. In Rayleigh criterion, combustion instability is triggered when the heat addition is in phase with acoustic oscillation. A Rijke type burner with a pre-mixed flame is built for investigating the effect of Reynolds number and equivalence ratio on thermoacoustic oscillation. The results suggest that the frequency of max, oscillation is dependent on Reynolds number and equivalence ratio whereas its magnitude is not a strong function of these two parameters.

  • PDF

Characteristics of Thermoacoustic Oscillation in Ducted Flame Burner (관형 연소기의 열음향학적 특성에 관한 연구)

  • 조상연;이수갑
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 1997.04a
    • /
    • pp.621-626
    • /
    • 1997
  • Combustion instability is a common phenomenon in a ducted flame burner and is known as accompanying low frequency oscillation. This is due to the interaction between unsteady heat release rate and sound pressure field, that is, thermoacoustic feedback. In Rayleigh criterion, combustion instability is triggered when the heat additions is in phase with acoustic oscillation. A Rijke type burner with a pre-mixed flame is built for investigating the effect of Reynolds number and equivalence ratio on thermoacoustic oscillation. In addition, the effect of wall temperature is presented. The results suggest that the frequency of max. oscillation is dependent on Reynolds number and equivalence ratio whereas its magnitude is not a strong function of these two parameters. On the other hand, the wall temperature distribution has much strong effects on the oscillation, even creates different mode of acoustic resonance.

  • PDF

Onset condition of the combustion-driven sound in a surface burner (표면 연소기의 연소진동음의 발생조건)

  • Kwon, Y.P.;Lee, J.W.;Lee, D.H.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.9 no.2
    • /
    • pp.221-228
    • /
    • 1997
  • A strong combustion-driven sound from a surface burner made of a perforated metal fiber plate for premixed gas was investigated to clarify the physical mechanism of its generation. A simple model was developed for the acoustic power generation in terms of the heat transfer response function and the acoustic impedance of the burner. The acoustic impedance of the perforated metal fiber placed on the open exit was measured and the heat release response of the burner to the oscillating flow associated with the acoustic disturbance was expressed in terms of a response function. It was found that the power is generated by the heat release in response to the downstream particle velocity, in contrast to the upstream velocity in the case of the Rijke oscillation driven by a heater placed in the lower half of a columm with upstream flow. The measured frequencies of the oscillation were in agreement with the estimated resonance frequencies and their excitation was varied with the combustion conditions. For the same fuel rate, the excited frequency increases with the air ratio if it is low but decreases with the ratio if not so low. Such frequency characteristics were explained by assuming a heat release response function with a time constant and it was shown that the excited frequency decreases as the time constant increases.

  • PDF

Active Control of Thermoacoustic Instability in Cylindrical Combustor with Low Speed Flow Field (저속 유동장이 있는 원통형 연소기에서의 열-음향학적 불안정에 대한 능동 제어 연구)

  • 조상연;이용석;이수갑;배충식
    • Journal of KSNVE
    • /
    • v.8 no.5
    • /
    • pp.914-921
    • /
    • 1998
  • Combusion instability due to thermoacoustic feedback in a ducted combustor usually excites severe noise and vibration, which could lead to result in the failure of the system or environmental dispute. In the present study, an active noise control(ANC) method with an adaptive algotithm is hired to suppress instability which has very discrete behavior in the frequency domain. Especially a feedback system is composed to evade hot environment of the combustor, and as a preliminary, the performance and stability of the controller is chekced by simulating the real situation with harmonic waves. Application to the real combustor showed serious reductions in sound pressure level by 20∼30 dB. It was also shown that the selected control system was very stable and effective.

  • PDF