A further study of the effects of water vapor concentration on the rate of combustion of an artificial graphite in humid air flow

✍ Scribed by K. Matsui; H. Tsuji; A. Makino

• Publisher: Elsevier Science
• Year: 1986
• Tongue: English
• Weight: 800 KB
• Volume: 63
• Category: Article
• ISSN: 0010-2180
• DOI: 10.1016/0010-2180(86)90008-8

✦ Synopsis

Test specimens of graphite (disk-shaped, 10 mm in diameter and 1 mm in thickness) were burned in the stagnation region of an impinging oxidizer flow under atmospheric pressure; the velocity gradient of the impinging oxidizer flow was 100 s-J. The surface temperature of the test specimen was kept constant during each experimental run by an external heat source in a range of 1200-1700K. Three groups of oxidizers containing water vapor were used. The first group consists of humid air having six H20 concentrations (0.0681, 0.641, 3.13, 3.63, 5.15, 7.41 tool m -3 at 0.101 MPa and 320-339K); the second group, O2-recovered humid air having a fixed 02 concentration and five H20 concentrations equal to, respectively, the higher five of those for the aforementioned humid air; the third group, N2-enriched air having a fixed H20 concentration and five 02 concentrations equal to, respectively, the higher five 02 concentrations for the aforementioned humid air. The following results have been obtained. (1) When the water vapor concentration in the oxidizer flow is low, water vapor actively suppresses the combustion rate. (2) As the water vapor concentration exceeds a certain value, the effect of water vapor to suppress actively the combustion rate diminishes. (3) When the water vapor concentration is high, water vapor actively augments the combustion rate in the high surface temperature range.