Author Contributions
Conceptualization, C.M.-R., C.H. and P.B.; methodology, C.M.-R., C.H., P.B. and R.P.; validation, C.M.-R., C.H., P.B. and R.P.; investigation R.P.; writing—original draft preparation, R.P.; writing—review and editing, C.M.-R., C.H., P.B., J.B. and R.P.; supervision, C.M.-R. All authors have read and agreed to the published version of the manuscript.
Figure 1.
View of the spray chamber with optical accesses.
Figure 1.
View of the spray chamber with optical accesses.
Figure 2.
Scheme of the experimental and optical setup; 1 Light ED source; 2 and 5 Concave mirrors; 3 Chamber; 4 Injector; 6 Plane mirror; 7 Adjustable diaphragm; 8 CMos FastCam (High speed camera).
Figure 2.
Scheme of the experimental and optical setup; 1 Light ED source; 2 and 5 Concave mirrors; 3 Chamber; 4 Injector; 6 Plane mirror; 7 Adjustable diaphragm; 8 CMos FastCam (High speed camera).
Figure 3.
Definition of spray characteristics for liquid spray of gasoline as an example, (a) Raw image, (b) Binarized image, (c) Rotated image and (d) Calculations.
Figure 3.
Definition of spray characteristics for liquid spray of gasoline as an example, (a) Raw image, (b) Binarized image, (c) Rotated image and (d) Calculations.
Figure 4.
Experimental conditions and vapor pressure curves of gasoline, ethanol [
23], and ammonia [
24].
Figure 4.
Experimental conditions and vapor pressure curves of gasoline, ethanol [
23], and ammonia [
24].
Figure 5.
Comparison of spray shape, 1 ms after the start of injection, obtained for liquid and liquid + vapor—left column: ammonia, middle column: gasoline, right column: ethanol—for 2 air density conditions and 3 ambient temperatures, 1ms after injection. The yellow section corresponds to flash boiling.
Figure 5.
Comparison of spray shape, 1 ms after the start of injection, obtained for liquid and liquid + vapor—left column: ammonia, middle column: gasoline, right column: ethanol—for 2 air density conditions and 3 ambient temperatures, 1ms after injection. The yellow section corresponds to flash boiling.
Figure 6.
Comparison of spray penetration for ammonia (continuous line), gasoline (dashed line), and ethanol (dotted line), (a) Tair = 20 °C and Pair = 2 bar, (b) Tair = 20 °C and Pair = 7 bar, (c) Tair = 120 °C and Pair = 2.69 bar, and (d) Tair = 120 °C and Pair = 9.39 bar.
Figure 6.
Comparison of spray penetration for ammonia (continuous line), gasoline (dashed line), and ethanol (dotted line), (a) Tair = 20 °C and Pair = 2 bar, (b) Tair = 20 °C and Pair = 7 bar, (c) Tair = 120 °C and Pair = 2.69 bar, and (d) Tair = 120 °C and Pair = 9.39 bar.
Figure 7.
Comparison of spray angle near the injector for ammonia (continuous line), gasoline (dashed line) and ethanol (dotted line), (a) Tair = 20 °C and Pair = 2 bar, (b) Tair = 20 °C and Pair = 7 bar, (c) Tair = 120 °C and Pair = 2.69 bar, and (d) Tair = 120 °C and Pair = 9.39 bar.
Figure 7.
Comparison of spray angle near the injector for ammonia (continuous line), gasoline (dashed line) and ethanol (dotted line), (a) Tair = 20 °C and Pair = 2 bar, (b) Tair = 20 °C and Pair = 7 bar, (c) Tair = 120 °C and Pair = 2.69 bar, and (d) Tair = 120 °C and Pair = 9.39 bar.
Figure 8.
Comparison at Tair = 120 °C between low air density (open grey symbol) and high air density (closed black symbol) of liquid + vapor spray angle near the injector for ammonia (continuous line), gasoline (dashed line), and ethanol (dotted line).
Figure 8.
Comparison at Tair = 120 °C between low air density (open grey symbol) and high air density (closed black symbol) of liquid + vapor spray angle near the injector for ammonia (continuous line), gasoline (dashed line), and ethanol (dotted line).
Figure 9.
Comparison of spray angle at half the penetration length for ammonia (continuous line), gasoline (dashed line) and ethanol (dotted line), (a) Tair = 20 °C and Pair = 2 bar, (b) Tair = 20 °C and Pair = 7 bar, (c) Tair = 120 °C and Pair = 2.69 bar, and (d) Tair = 120 °C and Pair = 9.
Figure 9.
Comparison of spray angle at half the penetration length for ammonia (continuous line), gasoline (dashed line) and ethanol (dotted line), (a) Tair = 20 °C and Pair = 2 bar, (b) Tair = 20 °C and Pair = 7 bar, (c) Tair = 120 °C and Pair = 2.69 bar, and (d) Tair = 120 °C and Pair = 9.
Figure 10.
Schematic explanation of the relation between spray geometry and spray angle at half the penetration length, (a) constant spray angle, (b) decrease in spray angle and (c) constant spray angle and then decrease in spray angle.
Figure 10.
Schematic explanation of the relation between spray geometry and spray angle at half the penetration length, (a) constant spray angle, (b) decrease in spray angle and (c) constant spray angle and then decrease in spray angle.
Figure 11.
Effect of
Pa/
Ps on spray penetration for ethanol and ammonia under various fuel temperatures and ambient pressure conditions from [
27] and this study.
Figure 11.
Effect of
Pa/
Ps on spray penetration for ethanol and ammonia under various fuel temperatures and ambient pressure conditions from [
27] and this study.
Figure 12.
Effect of flash boiling on the liquid + vapor spray angle at half the penetration length for a penetration length of 40 mm.
Figure 12.
Effect of flash boiling on the liquid + vapor spray angle at half the penetration length for a penetration length of 40 mm.
Figure 13.
Comparison of angle at half the penetration length for vapor + liquid spray of ammonia for a penetration length of 40 mm.
Figure 13.
Comparison of angle at half the penetration length for vapor + liquid spray of ammonia for a penetration length of 40 mm.
Figure 14.
Example at t = 1 ms of the relationship between vapor + liquid spray penetration and air density, temperature, and pressure.
Figure 14.
Example at t = 1 ms of the relationship between vapor + liquid spray penetration and air density, temperature, and pressure.
Figure 15.
Correlations of the temporal coefficients, (a) correlation with two time-dependent parameters, and (b) correlation with only one time-dependent parameter.
Figure 15.
Correlations of the temporal coefficients, (a) correlation with two time-dependent parameters, and (b) correlation with only one time-dependent parameter.
Figure 16.
Predicted VS measured values for all fuels during the adequate period, (a) correlation with two time-dependent parameters, and (b) correlation with only one time-dependent parameter.
Figure 16.
Predicted VS measured values for all fuels during the adequate period, (a) correlation with two time-dependent parameters, and (b) correlation with only one time-dependent parameter.
Table 1.
Experimental conditions for all fuels.
Table 1.
Experimental conditions for all fuels.
Ambient Temperature (°C) | Ambient Pressure (bar) | Air Density (kg/m3) |
---|
20 | 2 | 2.38 |
4 | 4.76 |
7 | 8.32 |
80 | 2.41 | 2.38 |
4.82 | 4.76 |
8.43 | 8.32 |
120 | 2.69 | 2.38 |
5.37 | 4.76 |
9.39 | 8.32 |
Table 2.
Experimental conditions for ammonia only.
Table 2.
Experimental conditions for ammonia only.
Ambient Temperature (°C) | Ambient Pressure (bar) | Air Density (kg/m3) |
---|
20 | 10 | 11.88 |
15 | 17.82 |
22.68 | 26.99 |
30 | 23.45 | |
40 | 24.23 | 26.99 |
50 | 25 | |
20 | 25 | 29.75 |
30 | 28.77 |
40 | 27.85 |
50 | 26.99 |
Table 3.
Exponent coefficients of ammonia, gasoline, and ethanol.
Table 3.
Exponent coefficients of ammonia, gasoline, and ethanol.
Fuel | af | bf | cf | af + cf | cf − bf |
---|
Ammonia | −1.41 | 0.53 | 0.99 | −0.42 | 0.46 |
Gasoline | −1.39 | 1.35 | 1.05 | −0.34 | −0.30 |
Ethanol | −1.28 | 1.15 | 0.94 | −0.34 | −0.21 |