Average droplet vaporization rates in partially prevaporized turbulent spray flames
29th International Symposium on Combustion, Sapporo, Japonya, 21 - 26 Temmuz 2002, ss.21, (Tam Metin Bildiri)
- Yayın Türü: Bildiri / Tam Metin Bildiri
- Doi Numarası: 10.1016/s1540-7489(02)80068-2
- Basıldığı Şehir: Sapporo
- Basıldığı Ülke: Japonya
- Sayfa Sayıları: ss.21
- Orta Doğu Teknik Üniversitesi Adresli: Evet
Özet
Lean partially prevaporized and premixed turbulent spray flames of n-heptane/air mixtures were investigated experimentally at ambient conditions of temperature and pressure. The effect of the global equivalence ratio, the droplet residence time in the prevaporization tube, and the initial spray droplet mean diameter for the structure of this kind of flame was studied. Measurements in the flame were performed for three equivalence ratios, for two residence times, and for three initial droplet mean diameters. For all flames, phase Doppler anemometry (PDA) was used to characterize the droplet velocities and diameters. From the PDA results, the local average vaporization rates K of the droplets within the flame were estimated. K depended mainly on the initial mean droplet diameter of the spray and on the spray turbulence intensity. The influence of the global equivalence ratio was explained in terms of the flame height and thus could be eliminated by utilizing the mean progress variable as parameter. The average vaporization rates within the spray flame were compared to those obtained for the vaporization of single droplets under various conditions of surrounding temperature and turbulence intensity. Original is an abstract.