An investigation into heat transfer from unseeded propane-air flames augmented with D.C. electrical power

✍ Scribed by I. Fells; J.H. Harker

• Publisher: Elsevier Science
• Year: 1968
• Tongue: English
• Weight: 517 KB
• Volume: 12
• Category: Article
• ISSN: 0010-2180
• DOI: 10.1016/0010-2180(68)90077-1

✦ Synopsis

Heat transfer measurements have been made beyond the discharge zone or an un.~cded d.c. augmented propaneair flame. Previous work has been confined to ~eeded a.¢. augmented flames. Measurements were carried out using a water-cooled, gross flow probe; temperatures were measured using the D-line reversal method with a stabilized carbon arc background source. The maximum total energy of the augmented flame at a boost ratio of unity was t5 kW. It was found that aulgmeating the flame (boost ratio 1"3) increased the heat flux by some 300 per cent and that heat transfer coefficients were earrela,ed by the general relation {Nu) = 0"615 (Re) °'46~' indicating that the Lewis number could be taken as unity. For the particular geometric configuration used the following empirical relations correlated the data:

(unaugmeated flames) (Nu) = (0.573 -0.0179m) (Re) °s (augmented flames) (Nu) ffi (0"573 -0~)1 llm)(Re) °s where m cm is the height of measurement above the water-cooled cathode. These relations hold for boost ratios in the range 0,45 to 1'40 within + 10 per cent.