Some new experimental observations of combustion characteristics near lean limit in a tube under microgravity

• Autorzy: Kawakami T. , Okajima S. , Teodorczyk A.
• Języki publikacji: EN

Abstrakty

EN

Experiments have been carried out with extremely lean, quiescent propane-air mixtures to examine the behavior of irregular flame propagation and to examine the lean limits of flame propagation in a tube under microgravity. The microgravity technique achieved in a freely falling chamber is employed because the realizations of symmetrical flame propagations in a tube are possible. Experimental conditions for the initial mixtures correspond to room temperature and 0.1 MPa and the fuel used is propane of 99.9% purity. The experimental results show that (1) though the lean limit of the flame propagation in a tube decreases with increasing diameter, it holds constant when the tube diameter is more than 50 mm, (2) with a large combustion tube, the lower flammability limit shifts to as low as . = 0.15 of equivalence ratio under microgravity, (3) the irregular flame fronts of cellular nature are observed in a narrow range of 0.35 < . < 0.55 under microgravity, (4) the lowest measured value of flame speed is of the order of 11.5 cm/s under microgravity which is less than half of that observed under normal gravity, and (5) the influence of radiation from the wall in a tube on flame speed appears negligible.

• Wydawca: Łukasiewicz Research Network - Institute of Aviation ; European Science Society of Powertrain and Transport KONES Poland ; Wydawnictwo Instytutu Technicznego Wojsk Lotniczych
• Czasopismo: Journal of KONES
• Rocznik: 2002
• Tom: Vol. 9, No. 1-2
• Strony: 110--116
• Opis fizyczny: Bibliogr.15 poz., rys.

Twórcy

autor

Kawakami T.

• Faculty of Engineering Hosei University, 3-7-2 Kajino-cho, Koganei-shi, Tokyo, 184-8584 Japan tel. [phone], fax[phone]

autor

Okajima S.

• Faculty of Engineering Hosei University, 3-7-2 Kajino-cho, Koganei-shi, Tokyo, 184-8584 Japan tel. [phone], fax[phone]

autor

Teodorczyk A.

• Warsaw University of Technology, ITC, Nowowiejska 25, 00-665 Warszawa, tel. [phone], fax [phone]

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