scholarly journals Evaporation and Ignition of a Fuel Droplet on a Hot Surface : Part 3, Effects of Initial Droplet Diameter

1979 ◽  
Vol 22 (171) ◽  
pp. 1266-1273 ◽  
Author(s):  
Masahiko MIZOMOTO ◽  
Akio MORITA ◽  
Shigeru IKAI
Keyword(s):  
Droplet Diameter ◽  
Fuel Droplet ◽  
Surface Part ◽  
Initial Droplet ◽  
Hot Surface

The evaporation and combustion of levitated arrays of two, three and five droplets at a hot surface

1988 ◽  
Vol 418 (1855) ◽  
pp. 365-382 ◽  
Keyword(s):  
Droplet Diameter ◽  
Flame Height ◽  
Linear Arrays ◽  
Initial Droplet ◽  
Surface Temperatures ◽  
Droplet Array ◽  
Burning Rates ◽  
Hot Surface

The interactions between droplets in several geometrical arrays in Leidenfrost evaporation and combustion on a hot surface were studied. Comparisons between evaporation and burning times of isolated droplets, two- and three-droplet linear arrays, and a five-droplet array (a centre droplet surrounded by four droplets) were made. The liquids studied were water, n -heptane, and n -hexadecane at 0.101 MPa and at surface temperatures above their respective Leidenfrost values. A range of centre distance to initial droplet diameter ratios, L / d 0 , were studied (2 < L / d 0 < ∞). The evaporation or burning rates of droplets in binary arrays were found to be identical to those of isolated droplets ( L / d 0 → ∞). The flames around each droplet, however, merged as the droplets were brought closer together. In three- and five-droplet arrays more significant interactions were observed, with the edge droplets in the arrays burning faster than the centre droplets. The results are explained on the basis of flame-height measurements for the arrays. In pure evaporation, though, the droplets evaporated without regard for their neighbours.

scholarly journals Evaporation and Ignition of a Fuel Droplet on a Hot Surface : Part 2, Ignition

1978 ◽  
Vol 21 (162) ◽  
pp. 1772-1779 ◽  
Author(s):  
Masahiko MIZOMOTO ◽  
Shigeru IKAI
Keyword(s):  
Fuel Droplet ◽  
Surface Part ◽  
Hot Surface

Evaporation and ignition of a fuel droplet on a hot surface (Part 4, model of evaporation and ignition)

1983 ◽  
Vol 51 ◽  
pp. 95-104 ◽  
Author(s):  
Masahiko Mizomoto ◽  
Shigeru Ikai ◽  
Akio Morita
Keyword(s):  
Fuel Droplet ◽  
Surface Part ◽  
Hot Surface

scholarly journals Evaporation and Ignition of a Fuel Droplet on a Hot Surface : Part 1, Evaporation

1978 ◽  
Vol 21 (162) ◽  
pp. 1765-1771 ◽  
Author(s):  
Masahiko MIZOMOTO ◽  
Hiroyasu HAYANO ◽  
Shigeru IKAI
Keyword(s):  
Fuel Droplet ◽  
Surface Part ◽  
Hot Surface

Ignition of Liquid Fuel Droplet in a Hot, Stagnant Oxidizing Atmosphere-Numerical Computations

1984 ◽  
Vol 2 (6) ◽  
pp. 400-414 ◽  
Author(s):  
Andrzej Teodorczyk
Keyword(s):  
Mathematical Model ◽  
Finite Element Method ◽  
Finite Element ◽  
Ambient Temperature ◽  
Oxygen Concentration ◽  
Liquid Fuel ◽  
Droplet Diameter ◽  
Fuel Droplet ◽  
The Finite Element Method ◽  
Initial Droplet

The paper describes the physical and mathematical model of the ignition of a liquid fuel droplet suddenly immersed in a hot oxidizing medium. The model was solved numerically by the finite element method. The ignition lags in terms of ambient temperature, oxygen concentration and initial droplet diameter were computed.

scholarly journals Hot Surface Ignition of A Composite Fuel Droplet

2015 ◽  
Vol 23 ◽  
pp. 01063 ◽  
Author(s):  
Dmitrii O. Glushkov ◽  
Pavel A. Strizhak ◽  
Ksenia Yu. Vershinina
Keyword(s):  
Fuel Droplet ◽  
Hot Surface Ignition ◽  
Surface Ignition ◽  
Composite Fuel ◽  
Hot Surface

scholarly journals Droplet Characteristics of Rotating Packed Bed in H2S Absorption: A Computational Fluid Dynamics Analysis

Processes ◽  
2019 ◽  
Vol 7 (10) ◽  
pp. 724
Author(s):  
Wang ◽  
Wu ◽  
Yang ◽  
Wang ◽  
Liu ◽  
...  
Keyword(s):  
Residence Time ◽  
Droplet Diameter ◽  
Packed Bed ◽  
Droplet Velocity ◽  
Radial Position ◽  
Selective Absorption ◽  
Rotating Speed ◽  
Initial Droplet ◽  
Rotating Packed Bed ◽  
Computational Fluid Dynamics Analysis

Rotating packed bed (RPB) has been demonstrated as a significant and emerging technology to be applied in natural gas desulfurization. However, droplet characteristics and principle in H2S selective absorption with N-methyldiethanolamine (MDEA) solution have seldom been fully investigated by experimental method. Therefore, a 3D Eulerian–Lagrangian approach has been established to investigate the droplet characteristics. The discrete phase model (DPM) is implemented to track the behavior of droplets, meanwhile the collision model and breakup model are employed to describe the coalescence and breakup of droplets. The simulation results indicate that rotating speed and radial position have a dominant impact on droplet velocity, average residence time and average diameter rather than initial droplet velocity. A short residence time of 0.039–0.085 s is credited in this study for faster mass transfer and reaction rate in RPB. The average droplet diameter decreases when the initial droplet velocity and rotating speed enhances. Restriction of minimum droplet diameter for it to be broken and an appropriate rotating speed have also been elaborated. Additional correlations on droplet velocity and diameter have been obtained mainly considering the rotating speed and radial position in RPB. This proposed formula leads to a much better understanding of droplet characteristics in RPB.

The Combustion of a Liquid Fuel Droplet during Forced Convection

1994 ◽  
Vol 12 (1) ◽  
pp. 44-61
Author(s):  
Andrzej Teodorczyk ◽  
Stanislaw Wójcicki
Keyword(s):  
Reynolds Number ◽  
Forced Convection ◽  
Droplet Diameter ◽  
Fuel Droplet ◽  
Combus Tion ◽  
Air Stream ◽  
Freely Suspended ◽  
High Reynolds ◽  
Additional Support ◽  
Physical And Mathematical Models

A new experimental technique was used to investigate single fuel droplet combustion during forced convection: the burning droplet was freely suspended in the controlled air stream, without any additional support. Based on the photo-records of the burning process, the characteristics of the change of square of droplet diameter with time were made and the actual values of burning constants were determined for four hydrocarbon fuels: ben zene, n-heptane, iso-octane and toluene. The experiments were also carried out under micro-gravity and free convection conditions for the same set of fuels. The investigations have allowed the comparison of the burning mechanism of a single droplet for the three different external conditions and have compared quantitatively the burning constants. On the basis of the color pictures of the droplet burning under forced convection conditions and the temperature and gas concentration measurements within the flame, the mechanism of combus tion of fuel droplet was explained. The physical and mathematical models of the process have been proposed which included the aerodynamics of the droplet located in the high Reynolds number air stream, the energy balance of the evaporating droplet and the chemical reaction in the flow. The models have made it possible to determine the quantitative dependence of the burning con stant of different kinds of fuels on Reynolds number, the flow field parameters and the physical and chemical parameters of the liquid and its close surround ings. The calculated values of the parameters describing the burning pro cess have been compared to the experimental data and to the results reported by other investigators. The model has revealed the importance of the feed back mechanism between physical processes involved during droplet combus tion.

The effect of initial diameter in spherically symmetric droplet combustion of sooting fuels

1994 ◽  
Vol 446 (1927) ◽  
pp. 255-276 ◽  
Keyword(s):  
Burning Rate ◽  
Rate Constants ◽  
Soot Formation ◽  
Droplet Diameter ◽  
Droplet Surface ◽  
Spherically Symmetric ◽  
Low Gravity ◽  
Initial Droplet ◽  
Initial Diameter ◽  
Burning Rates

The effect of initial droplet diameter on the burning rate of sooting fuels – n-heptane and 1-chloro-octane – was examined experimentally at low gravity. A 1.2s drop tower provided a low gravity environment to minimize buoyancy and achieve spherically symmetric flames for stationary droplets. Free-floating and fibre-supported droplets were burned, and both techniques gave matching results for droplets of similar initial diameter. Burning rate constants for both fuels were measured for a large number of droplets ranging from 0.4 to 1.1 mm in initial diameter. Results showed that burning rate constants decreased monotonically as the initial droplet diameter was increased above 0.6 mm for both fuels. This decrease was considered to be due to the observed increase in soot formation and accumulation in a shell-like structure inside the flame of the larger droplets. The increased collection of soot inside the larger droplet flames reduced the proportional heat release from the flame and may have acted as a barrier to heat transfer from the flame to the droplet. Flame-to-droplet diameter ratio increased monotonically with time, thus suggesting that quasi-steady combustion was not achieved. The flames and soot shells for 1-chloro-octane droplets with their lower burning rates remained closer to the droplet surface than similarly sized n-heptane droplets.

Sign in / Sign up

Export Citation Format

Share Document