# Conditions for and Characteristics of the Dispersion of Gel Fuel Droplets during Ignition
## 3 Results and Discussion
\begin{table}
\begin{tabular}{c c c c} \hline \multirow{2}{*}{**Liquid**} & \multicolumn{3}{c}{**OWRK Method**} & \multirow{2}{*}{\(\sigma_{L}\)**, mN/m (Du**} \\ \cline{2-3}  & \(\sigma_{L}^{p}\)/\(\sigma_{L}^{D}\), mN/m & \(\sigma_{L}\)=\(\sigma_{L}^{p}\)/\(\sigma_{L}^{D}\), mN/m & **Nouy/Wilhelmy Methods** \\ \hline \multicolumn{4}{c}{**First Group (Polar Liquids)**} \\ \hline Water * & 51.0/21.8 & 72.80 & 72.56 \(\pm\) 0.03/72.78 \(\pm\) 0.01 \\ Monoethanolamine & 28.8/18.0 & 46.80 & 45.77 \(\pm\) 0.02/46.00 \(\pm\) 0.01 \\ \hline \multicolumn{4}{c}{**Second Group (Dispersive Liquids with a High Value of the Polar Part)**} \\ \hline Glycerol & 26.0/35.0 & 61.00 & 59.92 \(\pm\) 0.06/60.88 \(\pm\) 0.15 \\ Ethylene glycol & 17.6/26.4 & 44.00 & 43.52 \(\pm\) 0.02/43.49 \(\pm\) 0.01 \\ \hline \multicolumn{4}{c}{**Third group (Dispersive Liquids with a Low Value of the Polar Part)**} \\ \hline Acetone & 2.4/24.1 & 26.50 & 26.12 \(\pm\) 0.09/25.88 \(\pm\) 0.02 \\ Ethyl alcohol 95\% & 3.4/19.0 & 22.40 & 22.08 \(\pm\) 0.04/22.40 \(\pm\) 0.01 \\ \hline \multicolumn{4}{c}{**Fourth Group (Dispersive Liquids)**} \\ \hline Diiodomethane * & 0.0/50.8 & 50.80 & 49.71 \(\pm\) 0.02/49.79 \(\pm\) 0.01 \\ Dodecane & 0.01/26.8 & 26.81 & 25.78 \(\pm\) 0.03/26.10 \(\pm\) 0.02 \\ Synthetic engine oil & 1.2/30.2 & 31.40 & 30.78 \(\pm\) 0.05/31.50 \(\pm\) 0.06 \\ Compressor oil & 0.01/29.5 & 29.51 & 28.12 \(\pm\) 0.19/29.7 \(\pm\) 0.09 \\ Oil TEDEX TU 32 & 0.8/32.1 & 32.90 & 32.85 \(\pm\) 0.09/32.84 \(\pm\) 0.05 \\ \hline \end{tabular}
* Test liquids; their values of \(\sigma_{L}^{p}\) and \(\sigma_{L}^{D}\) were chosen from Ref. [28].  
\end{table} 
Table 3: Surface tensions of liquids determined by using the Du Nouy and Wilhelmy methods and the polar and dispersive parts of the surface tension and their sum determined by using the OWRK method. \begin{table}
\begin{tabular}{c c c} \hline \hline \multicolumn{2}{c}{**Composition of Binary Mixture**} & \multicolumn{1}{c}{**Recorded Process**} \\ \hline
**Belonging to Groups 1–4** & **Belonging to Groups 1–4** & **(Evaporation/Boiling/** \\
**(Table 3) of the** & **(Table 3) of the** & **Puffing/Microexplosion)** \\
**First Component * & **Second Component * & \\ \hline
1 st group & 1 st group & Boiling \\
2 nd group & 2 nd group & Boiling \\
3 rd group & 3 rd group & Evaporation/Boiling ** \\
4 th group & 4 th group & Boiling \\
1 st group & 2 nd group & Boiling/Puffing ** \\
1 st group & 3 rd group & Boiling \\
1 st group & 4 th group & Microexplosion/Puffing ** \\
2 nd group & 3 rd group & Boiling \\
2 nd group & 4 th group & Puffing/Boiling ** \\
3 rd group & 4 th group & Boiling \\ \hline \hline \end{tabular}  
* The liquids from Table 3 were taken as the components. **Boiling or puffing was recorded in 2–3 experiments of the 10 experiments conducted under identical conditions. Microexplosions were recorded in the rest of the 7–8 experiments of the 10 experiments.  
\end{table} 
Table 4: Experimental results of the onset of evaporation, boiling, puffing, and microexplosion for binary liquid droplets subjected to high-temperature heating. Figure 3: _Cont._Figure 3: Typical frames of videograms illustrating the four mechanisms of physical and chemical processes during the high-temperature heating of binary liquids: (**a**) evaporation (acetone–95% ethyl alcohol); (**b**) boiling (water-acetone); (**c**) puffing (ethylene glycol–compressor oil); (**d**) microexplosion (monoethylamine–diiodomethane). According to the \"like dissolves like\" approach [24], liquids belonging to the same group mutually dissolved. It can be seen from Table 4 that the binary liquid droplets consisting of components characterized by mutual solubility evaporated or boiled. A phase transition in the evaporation mode (without boiling/puffing/microexplosion) was recorded during the heating of a droplet consisting of components from the third group (dispersive liquids with a low value of the polar part).