# Secondary Atomization of Fuel Oil and Fuel Oil/Water Emulsion through Droplet-Droplet Collisions and Impingement on a Solid Wall

^{*}

## Abstract

**:**

## 1. Introduction

## 2. Materials and Methods

#### 2.1. Type of Fuel

#### 2.2. Secondary Droplet Atomization Schemes

_{a}= 10–20 µm; average peak to valley height R

_{z}= 40–80 µm).

_{d}). For droplet atomization using droplet–droplet collisions, we used a setup from [41] (Figure 1). Droplet impingement on a solid substrate was provided by an experimental setup from [51] (Figure 1).

#### 2.3. Variable Parameters and Recorded Characteristics; Measurement Errors

_{d}), size (R

_{d}), and impact angle (α

_{d}). The systematic error in these experiments was as follows: 2.1% for droplet velocity measurement, 3% for air flow velocity measurement, 1.6% for droplet radius measurement, and 2.3% for impact angle measurement. Random errors are shown as confidence intervals on characteristic curves. The measured parameters were used to calculate dimensionless numbers, such as the Weber number We = (2·R

_{d}·ρ·U

_{d}

^{2})/σ, Reynolds number Re = ρ·2R

_{d1}·U

_{rel}/µ, and Ohnesorge number Oh = µ/(ρ·σ·2·R

_{d})

^{0.5}. These dimensionless criteria are used for generalizing the research findings because they reflect the joint contribution of different liquid properties. In particular, the Reynolds number takes into account the inertial force to viscosity force ratio and the Ohnesorge number reflects viscosity, inertia, and surface tension, whereas the Weber number determines the ratio of the liquid’s inertia to its surface tension. When calculating the values of the Weber, Ohnesorge, and Reynolds numbers, we used the size of the smaller droplet from the two colliding ones according to the methods described in [57,58,59].

_{d1}+ R

_{d2}) is used to reflect the impact centricity. Figure 2 presents the schemes used for recording the measurement parameters of droplet–droplet collisions and droplet impingement on a solid wall.

_{rel}= (U

_{d1}

^{2}+ U

_{d2}

^{2}− 2·U

_{d1}·U

_{d2}·cos(α

_{d}))

^{1/2}) (Figure 2). The parameter b is a segment perpendicular to the vectors marked off in parallel to the resultant velocity vector. Therefore, the linear impact parameter (B) reflects the droplet sizes and velocities, the impact angle, and the distance between the droplets’ centers of mass. The linear impact parameter is a dimensionless linear parameter of a collision describing the centricity of impacts of the droplets. The value B = 0 corresponds to a frontal collision and B = 1 corresponds to a tangent collision. The parameter B is determined before the collision and is the distance b between the centers of two droplets in a plane perpendicular to the relative velocity vector, and is normalized to the average droplet diameter [57]. The impact angle in binary collisions of droplets has a significant effect on the resulting velocity of interaction between droplets. This effect is considered when calculating the resulting droplet velocity using the least-squares method. The highest kinetic energy during the collision of droplets corresponds to impact angles close to 0° and 90° [60]. In this case, the contact area of the droplets is a maximum, their kinetic energy is also a maximum, and the interaction proceeds intensively due to internal shear stresses.

_{0}= 4·π·(R

_{d1}

^{2}+ R

_{d2}

^{2}) and the surface area of newly formed fragments was written as S

_{1}= 4·π·∑N·r

_{d}

^{2}.

_{0}and S

_{1}, we controlled the equality of the liquid volumes before and after the collisions. For this equality to hold, the calculated number of child droplets included the liquid fragments both in and out of focus of the video camera. All the child droplets were assumed to have the same average size. Preliminary experiments using three video cameras, reproducing the conditions of three-dimensional video recording, justified this approach: the number and the average size of child droplets calculated in this way did not differ by more than 6–8% from the results obtained using three cameras. A similar calculation was performed for the collision of fuel oil/water emulsion droplets with a substrate.

_{d}= 0.1–7 m/s). The regime maps were constructed in the coordinate system of the Weber number and linear interaction parameter B, which also indirectly reflected the impact angle α

_{d}. Using the experimental points obtained on the maps, we determined the boundary points reflecting the transition between fuel droplet interaction regimes. We then plotted a boundary connecting these points. An approximation boundary line was drawn if 95% of the points were within the domain of a certain regime. The B(Re), We(Oh), We(Re), and Re(Oh) regime maps were also constructed in a conventional form [38,61,62].

## 3. Results and Discussion

#### 3.1. Main Patterns of Collisions under Study

#### 3.2. Droplet–Droplet Collision Regime Maps

_{1}/S

_{0}, we found that at a Weber number of approximately 200, droplets of a two-component fuel are atomized 50% more effectively than those of fuel oil, and fuel oil colliding with water provides a 100% greater efficiency.

#### 3.3. Fuel Oil Droplets Impinging on a Solid Wall

_{x}, NO

_{x}, and particulate matter emissions. These effects are achieved by the secondary atomization of fuel oil droplets. The experimental findings from this research can help control the secondary atomization of fuel oil droplets in combustion chambers.

#### 3.4. Calculation of Droplet Energies in the Interaction Zone

#### 3.4.1. Energy Balance during Binary Fuel Droplet Collisions

_{i}comprises the initial kinetic energy KE

_{ii}of the part of droplets directly involved in the collision and the initial kinetic energy KE

_{ni}of the part of droplets that does not take part in the interaction. The energy KE

_{ii}can be represented in the form of the energy KE

_{sii}and the kinetic energy KE

_{dii}. KE

_{sii}stretches the droplet along the radial direction and gradually transforms into the bridge surface tension energy and the viscous dissipation energy. KE

_{dii}deforms the droplet along the radial direction and gradually transforms into the viscous dissipation energy. The kinetic energy of the parts that are not involved in the interaction includes the droplet-stretching energy KE

_{sni}and KE

_{rni}, which deforms the droplet along the radial direction at the initial interaction stage and makes the droplet swirl when the deformation reaches its maximum.

_{rni}gradually transforms into the viscous dissipation energy. In this case, kinetic energy can be written as [69]:

_{i}= KE

_{ii}+ KE

_{ni}= KE

_{sii}+ KE

_{dii}+ KE

_{sni}+ KE

_{rni};

_{sii}= 1/2·ρ·[V

_{Si}·(U

_{S}·sin(α

_{d}))

^{2}+ V

_{Li}·(U

_{L}·sin(α

_{d}))

^{2}];

_{dii}= 1/2·ρ·[V

_{Si}·(U

_{S}·cos(α

_{d}))

^{2}+ V

_{Li}·(U

_{L}·cos(α

_{d}))

^{2}];

_{sni}= 1/2·ρ·[(V

_{S}− V

_{Si})·(U

_{S}·sin(α

_{d}))

^{2}+ (V

_{L}− V

_{Li})·(U

_{L}·sin(α

_{d}))

^{2}];

_{rni}= 1/2·ρ·[(V

_{S}− V

_{Si})(U

_{S}·cos(α

_{d}))

^{2}+ (V

_{L}− V

_{Li})(U

_{L}·cos(α

_{d}))

^{2}].

_{Li}and V

_{Si}are the volumes of the interaction zones in the larger and smaller droplets and V

_{L}and V

_{S}are the volumes of the larger and smaller droplets.

_{Li}= χ

_{L}·V

_{L};

_{Si}= χ

_{S}·V

_{S};

_{L}= 1 − (2 − τ)

^{2}·(1 + τ)/4; for h > D

_{L}/2;

_{L}= τ

^{2}·(3 − τ)/4; for h ≤ D

_{L}/2;

_{S}= 1 − (2·Δ − τ)

^{2}·(Δ + τ)/(4·Δ

^{3}); for h > D

_{S}/2;

_{S}= τ

^{2}·(3·Δ − τ)/(4·Δ

^{3}); for h ≤ D

_{S}/2;

_{L}+ D

_{S})·(1 − B);

_{L}and χ

_{S}are the coefficients reflecting the interaction zones in the larger and smaller droplets; h is the length of the interaction zone; τ is the impact angle coefficient; D

_{S}is the initial diameter of the smaller droplet; and D

_{L}is the initial diameter of the larger droplet.

^{3})(3·(1 + Δ)·(1 − B)·(Δ

^{3}·χ

_{S}+ χ

_{L}))

^{1/2}/((1 − α

_{3})·Δ

^{2}·B

^{2}).

_{L}≈ 0.001 m, D

_{S}≈ 0.001 m) collide head on, i.e., B ≈ 0.8, Δ = 1. The coefficients reflecting the interaction zone of the larger and smaller droplets will take the following values: χ

_{L}= 0.104; length of the interaction zone h ≤ D

_{L}/2; χ

_{S}= 0.104 for h ≤ D

_{S}/2. The critical Weber number for Equation (14) will be We = 52.04. Let us perform similar calculations for the two-component fuel containing 30% of transformer oil and 70% of water: D

_{L}≈ 0.0009 m, D

_{S}≈ 0.00095 m, B ≈ 0.6, Δ = 0.947, χ

_{L}= 0.337; χ

_{S}= 0.368. The critical Weber number We = 123.17. For the two-component fuel with 90 vol% of fuel oil and 10 vol% of water, the parameters will look as follows: D

_{L}≈ 0.0009 m, D

_{S}≈ 0.00095 m, B ≈ 0.6, Δ = 0.947, χ

_{L}= 0.337; χ

_{S}= 0.368. The critical Weber number We = 166.64.

_{sii}+ VDE

_{dii}+ VDE

_{sni}+ VDE

_{rni}.

_{sii}, KE

_{sni}, KE

_{dii}, and KE

_{rni}are converted into parts of viscous dissipation energy VDE

_{sii}, VDE

_{dii}, VDE

_{sni}, and VDE

_{rni}, respectively:

_{sii}= α

_{3}·KE

_{sii};

_{sii}= α

_{3}·KE

_{sii};

_{dii}= α

_{4}·KE

_{dii};

_{rni}= α

_{5}·KE

_{rni},

_{2}, α

_{3}, α

_{4}, and α

_{5}are viscous dissipation coefficients.

_{dii}fully transforms into the viscous dissipation energy; hence, α

_{4}= 1.

_{rni}− VDE

_{rni}.

_{es}= KE

_{i}− VDE − RE ≥ SE

_{lig},

_{lig}is the surface tension energy of the bridge:

_{lig}= (2·σ·[π·h·(V

_{Si}+ V

_{Li})])

^{0.5}.

_{L}≈ 0.00095 m, D

_{S}≈ 0.0009 m, U

_{L}≈ 1.3 m/s, U

_{S}≈ 1.1 m/s, head-on collision, i.e., B ≈ 0 and α

_{d}≈ 90°. The total effective stretching energy KE

_{es}equals 1.06 J and the viscous dissipation energy is 4.24 J. The kinetic energy at the initial moment KE

_{i}amounts to 5.31 J. The bridge surface tension energy SE

_{lig}at the moment of maximum deformation is 0.029 J. The rotation energy RE equals 6.86·10

^{−6}J.

^{−6}≥ 0.029; 1.06 > 0.029.

_{L}≈ 0.00095 m, D

_{S}≈ 0.0009 m, U

_{L}≈ 1.5 m/s, U

_{S}≈ 1.2 m/s, B ≈ 0, and α

_{d}≈ 90°. The total effective stretching energy KE

_{es}= 0.96 J and the viscous dissipation energy equals 3.83 J. The kinetic energy at the initial moment KE

_{i}amounts to 4.78 J. The bridge surface tension energy SE

_{lig}at the moment of maximum deformation is 0.022 J. The rotation energy RE equals 2.1·10

^{−5}J.

^{−5}≥ 0.022; 0.96 > 0.022.

_{L}≈ 0.00095 m, D

_{S}≈ 0.0009 m, U

_{L}≈ 1.5 m/s, U

_{S}≈ 1.2 m/s, B ≈ 0, and α

_{d}≈ 90°, the total effective stretching energy KE

_{es}= 1.12 J and the viscous dissipation energy equals 4.48 J. The kinetic energy at the initial moment KE

_{i}amounts to 5.60 J. The bridge surface tension energy SE

_{lig}at the moment of maximum deformation is 0.063 J. The rotation energy RE is 1.8·10

^{−5}J.

^{−5}≥ 0.063; 1.12 > 0.063.

#### 3.4.2. Energy Balance during Fuel Droplet Impingement on a Solid Surface

_{dr}is the kinetic energy of the falling droplet; E

_{S0}, E

_{P0}and E

_{Ss}, E

_{Ps}are the surface and potential energy of a droplet before and after collision, respectively; E

_{sd}is the post-collision kinetic energy of droplets (energy of spreading of a droplet over a solid surface after collision); E

_{θ}is the energy from the work performed by the radial forces applied from the wall to the contact line; and E

_{D}is the viscous dissipation energy (the dissipation losses due to viscosity when a droplet spreads after collision). Potential energy (E

_{P0}, E

_{Ps}) makes the smallest contribution compared to other components of Equation (23), so it can be neglected [71].

_{d}

^{2}σ and obtain the following equation:

## 4. Technology Development Using Experimental Results

- (i)
- The number of secondary fragments increases exponentially with an increase in the Weber numbers. The free surface area of secondary fragments more than doubles with an increase in the parent droplet velocity. This leads to a reduction in the secondary droplet size and an increase in their number. We compared the free surface areas of droplets before and after collision to find that, at a Weber number of approximately 200, droplets of a two-component fuel are atomized 50% more effectively than those of fuel oil, and fuel oil colliding with water provides a 100% greater efficiency.
- (ii)
- The critical thermal conditions for combined breakup were found to depend on the substrate temperature and parent droplet size, as well as water to fuel oil concentration ratio. It was established that adding 5–30% of water to fuel oil and heating it to 80 °C reduced the size of secondary fragments by 40–70% and increased their number by 50–65%. The optimal wall surface temperature for the interaction with fuel oil/water droplets is 300 °C. At this temperature, we observed the maximum droplet breakup due to the absence of the Leidenfrost effect.
- (iii)
- For fuel oil droplets to be atomized effectively, their velocity must be 3 m/s and their size must range from 0.4 mm to 0.7 mm. These parameters provide consistent atomization of fuel oil droplets colliding with a heated solid wall and with each other.

## 5. Conclusions

- (i)
- The secondary atomization scheme for droplets of water-free fuel oil and fuel oil/water emulsion through collisions with each other and with water droplets provides a relatively significant increase in the liquid surface area (S
_{1}/S_{0}> 3). The required temperature of the fuel oil to be supplied to the droplet collision zone is 80 °C. The optimal substrate temperature for the atomization of two-component droplets (90 vol% fuel oil and 10 vol% water) is approximately 300 °C. The secondary atomization of fuel oil/water emulsion droplets by their impingement on a heated solid wall makes it possible to reduce the typical sizes of liquid fragments by a factor of 40–50. - (ii)
- We have plotted droplet collision regime maps and established the critical Weber and Ohnesorge numbers, as well as the critical values of the dimensionless linear interaction parameter, which reflect the threshold conditions of extensive droplet disruption. The disruption of fuel oil droplets with 10 vol% of water colliding with each other is provided at a critical Weber number of approximately 150. For fuel oil droplets colliding with water droplets, this number decreases to approximately 50. We have also shown the role of liquid heating in the occurrence of the collision regimes under study. Droplets of pure fuel oil and fuel oil with added water undergo the most significant atomization when impinging on a heated solid wall with a certain layer of fuel adhering to it.

## Supplementary Materials

## Author Contributions

## Funding

## Data Availability Statement

## Conflicts of Interest

## Nomenclature

B | linear approach parameter, mm; |

B | dimensionless linear interaction parameter; |

D_{d} | initial droplet diameter, mm; |

D_{max} | diameter at the moment of droplet spreading on the surface, mm; |

$\overline{D}$ | dimensionless diameter; |

D_{S} | initial diameter of the smaller droplet, m; |

D_{L} | initial diameter of the larger droplet, m; |

E_{D} | viscous dissipation energy, J; |

E_{θ} | energy from the work performed by the radial forces applied from the wall to the contact line, J; |

E_{dr} | kinetic energy transformed into rotational energy and viscous dissipation energy, J; |

E_{sd} | post-collision kinetic energy of droplets, J; |

E_{P0} and E_{Ps} | potential energy of a droplet before and after collision, J; |

E_{S0} and E_{Ss} | surface energy of a droplet before and after collision, J; |

h | deformed droplet height, m; |

h_{max} | droplet height at the moment of droplet spreading on the surface, mm; |

Oh | Ohnesorge number; |

N | number of newly formed post-collision droplets, pcs; |

Re | Reynolds number; |

R_{d1}, R_{d2} | radius of the first and second droplets, m; |

r_{d} | radius of the post-collision droplet, m; |

R_{a} | arithmetical mean deviation of the profile, m; |

R_{av} | average droplet radius; |

R_{z} | average peak-to-valley roughness, m; |

S_{0} | free surface area of droplets before collision, m^{2}; |

S_{1} | free surface area of post-collision droplets, m^{2}; |

S_{1}/S_{0} | ratio of the free surface area of droplets after and before collision; |

KE_{i}, KE_{ii}, KE_{ni}, KE_{sii}, KE_{dii}, KE_{sni}, KE_{rni} | kinetic energies of stretching separation, J; |

KE_{es} | kinetic energy of stretching separation, J; |

SE_{lig} | surface tension energy of the bridge, J; |

T | temperature of the composition, °C; |

T_{s} | temperature of the solid wall, °C; |

U_{d1}, U_{d2} | velocity of the first and second droplets, m/s; |

U_{S} | velocity of the smaller droplet accounting for relative droplet velocity, m/s; |

U_{L} | velocity of the larger droplet accounting for relative droplet velocity, m/s; |

U_{d} | velocity of the droplet before collision, m/s; |

U_{rel} | resulting (relative) velocity of droplet, m/s; |

VDE | dissipation energy, J; |

VDE_{sii}, VDE_{dii}, VDE_{sni}, VDE_{rni} | dissipation energy during stretching separation, J; |

RE | revolution energy, J; |

V_{li} | volume of the interaction zone of the large droplet, m^{3}; |

V_{si} | volume of the interaction zone of the smaller droplet, m^{3}; |

V_{L} | volume of the large droplet, m^{3}; |

V_{S} | volume of the smaller droplet, m^{3}; |

We | Weber number; |

$\overline{\mathsf{\tau}}$, ${\overline{h}}_{\mathrm{max}}$ | dimensionless constants. |

Greek symbols | |

α_{d} | impact angle, °; |

α_{1,} α_{2,} α_{3,} α_{4,} α_{5} | dissipation factors; |

ρ | density, kg/m^{3}; |

σ | surface tension, N/m; |

µ | dynamic viscosity, Pa∙s; |

Δ | ratio of droplet–droplet radii; |

τ | impact angle coefficient; |

χ_{L} | coefficient accounting for the interaction zone of the larger droplet; |

χ_{S} | coefficient accounting for the interaction zone of the smaller droplet; |

〈θ〉 | average dynamic wettability angle, °. |

Abbreviations | |

BO | bounce; |

CO | coalescence; |

CoR | coefficient of restitution; |

DI | disruption; |

SE | separation. |

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**Figure 1.**Scheme of experimental setup for droplet–droplet collisions (

**a**) and droplet impingement on solid substrates (

**b**): 1—fuel container; 2—fuel feeding nozzle; 3—fuel oil/water emulsion feeding pipeline; 4—magnetic stirrer; 5—high-speed video camera; 6—collision area; 7—spotlight; 8—collector of liquid fragments; 9—substrate; 10—gas burner.

**Figure 2.**Recording schemes of the measurement parameters of droplet–droplet collisions (

**a**) and droplet impingement on a solid wall (

**b**).

**Figure 3.**Images of droplet–droplet collisions (T ≈ 80 °C): (

**a**)—coalescence of fuel oil droplets; (

**b**)—bounce of fuel oil droplets; (

**c**)—disruption of two-component fuel droplets (90 vol% fuel oil, 10 vol% water); (

**d**)—bounce of two-component fuel droplets (90 vol% fuel oil, 10 vol% water); (

**e**)—disruption of fuel oil droplets colliding with water droplets; (

**f**)—coalescence of fuel oil and water droplets.

**Figure 4.**Video frames of droplets impinging on a heated solid surface: (

**a**,

**b**)—disruption of two-component fuel droplets (90 vol% fuel oil, 10 vol% water, T ≈ 80 °C; U

_{d}≈ 2.1 m/s) (at T

_{s}≈ 300 °C); (

**c**,

**d**)—two-component fuel droplets (90 vol% fuel oil, 10 vol% water, T ≈ 80 °C; U

_{d}≈ 2.3 m/s) impinging on a solid wall (at T

_{s}≈ 200 °C).

**Figure 5.**Collision regime maps of typical compositions accounting for the dimensionless linear interaction parameter: (

**a**) 1—CWS (30 wt% coal, 70 wt% water) [41]; 2—two-component fuel (30% transformer oil, 70% water) [41]; 3—CWSP (30 wt% coal, 25 wt% transformer oil, 45 wt% water) [41]; (

**b**) 4—water [41]; 5—fuel oil; (

**c**) 1–4—CWS (30 wt% coal, 70 wt% water) [41]; 5,6—two-component fuel (30% transformer oil, 70% water) [41]; 7–9—CWSP (30 wt% coal, 25 wt% transformer oil, 45 wt% water) [41]; 10–13—fuel oil; 14–17—water [41]; 1,5,7,10,14—disruption; 2,6,8,11,15—coalescence; 3,12,16—bounce; 4,9,13,17—separation.

**Figure 6.**Collision regime maps of typical compositions accounting for the dimensionless linear interaction parameter: (

**a**) 1—fuel oil; 2—collision of fuel oil and water droplets; 3—two-component fuel (90 vol% fuel oil, 10 vol% water); 4—two-component fuel (85 vol% fuel oil, 15 vol% water); 5—two-component fuel (70 vol% fuel oil, 30 vol% water); (

**b**) 1–4—collision of fuel oil and water droplets; 4–6—fuel oil; 7–9—two-component fuel (90 vol% fuel oil, 10 vol% water); 1,5,7—disruption; 2,6,8—coalescence; 3,9—bounce; 4—separation.

**Figure 7.**Post-collision to pre-collision free surface area ratio against Weber number (

**a**) and Reynolds number (

**b**): 1—water [41]; 2—two-component fuel (90 vol% fuel oil, 10 vol% water); 3—collision of fuel oil and water droplets; 4—fuel oil.

**Figure 8.**Collision regime maps accounting for inertia, friction, surface tension, and viscosity according to experimental data (

**a**,

**b**): 1–4—collision of fuel oil and water droplets; 5,6—fuel oil; 7–9—two-component fuel (90 vol% fuel oil, 10 vol% water); 1,5,7—disruption; 2,6,8—coalescence; 3,9—bounce; 4—separation and data from [65] (

**c**) 1—coalescence; 2—separation; 3—disruption.

**Figure 9.**Collision regime map for a droplet impinging on a surface accounting for Weber and Ohnesorge (

**a**), Weber and Reynolds (

**b**), and Reynolds and Ohnesorge (

**c**) numbers. Rounds denote first droplet spreading and coalescing with subsequent ones; squares refer to disruption: 1,2—two-component fuel (90 vol% fuel oil, 10 vol% water); 3,4—water [51]; 5,6—two-component fuel (30 vol% transformer oil, 70 vol% water) [51]; 7,8—slurry (30 wt% coal, 70 wt% water) [51].

**Table 1.**Fuel compositions used in the experiments and their properties. The table also contains data on the compositions used for the comparison of collision regimes and outcomes.

Composition Name | Initial Temperature T_{d}, °C | Density ρ, kg/m^{3} | Surface Tension σ, N/m | Dynamic Viscosity µ, Pa·s |
---|---|---|---|---|

Water | 20/80 | 998/965 | 0.073/0.063 | 0.0010/0.00036 |

Fuel oil | 20/80 | 1016/935 | 0.052/0.030 | 3.9/0.013 |

95 vol% of fuel oil, 5 vol% of water | 20/80 | 1014/937 | 0.053/0.032 | 3.02/0.156 |

90 vol% of fuel oil, 10 vol% of water | 20/80 | 1013/939 | 0.054/0.033 | 12.2/0.157 |

85 vol% of fuel oil, 15 vol% of water | 20/80 | 1012/941 | 0.055/0.035 | 14.81/0.238 |

70 vol% of fuel oil, 30 vol% of water | 20/80 | 1010/946 | 0.058/0.040 | 16.73/0.274 |

CWS (30 wt% coal, 70 wt% water) [41] | 20/80 | 1126/1096 | 0.247/0.200 | 0.0033/0.0008 |

Two-component fuel (30% transformer oil, 70% water) [41] | 20/80 | 963/930 | 0.057/0.046 | 0.0069/0.0012 |

CWSP (30 wt% coal, 25 wt% transformer oil, 45 wt% water) [41] | 20/80 | 1064/1034 | 0.190/0.152 | 0.0072/0.0013 |

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**MDPI and ACS Style**

Islamova, A.; Tkachenko, P.; Shlegel, N.; Kuznetsov, G.
Secondary Atomization of Fuel Oil and Fuel Oil/Water Emulsion through Droplet-Droplet Collisions and Impingement on a Solid Wall. *Energies* **2023**, *16*, 1008.
https://doi.org/10.3390/en16021008

**AMA Style**

Islamova A, Tkachenko P, Shlegel N, Kuznetsov G.
Secondary Atomization of Fuel Oil and Fuel Oil/Water Emulsion through Droplet-Droplet Collisions and Impingement on a Solid Wall. *Energies*. 2023; 16(2):1008.
https://doi.org/10.3390/en16021008

**Chicago/Turabian Style**

Islamova, Anastasia, Pavel Tkachenko, Nikita Shlegel, and Genii Kuznetsov.
2023. "Secondary Atomization of Fuel Oil and Fuel Oil/Water Emulsion through Droplet-Droplet Collisions and Impingement on a Solid Wall" *Energies* 16, no. 2: 1008.
https://doi.org/10.3390/en16021008