Effects of Injection Timing and Injection Volume on the Combustion and Emissions of a Two-Stroke Kerosene Direct Injection Engine
Round 1
Reviewer 1 Report
No block diagram of the experimental setup (regarding the engine shown in Picture 3 and 4) was presented.
No information about the measurement system (i.e. data acquisition device, control software etc.) that was used during experiments was given. No values of other measurement parameters (sampling time and resolution) were also presented.
The ignition energy value (line 114) most likely is 30 mJ, not 30 MJ.
There is no clear distinction between the experimental results and results of the numerical simulation - Figure 9 shows experimental data or simulation results?
It is not clear which data in the paper came from the prototype engine presented.
In the Conclusion section, some additional design suggestion should be included - for instance, what optimal operational parameters could be recommended for the engine/fuel configuration discussed in the paper.
Author Response
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Author Response File: 
Author Response.pdf
Reviewer 2 Report
This article analyzes the effect of injection timing and volume of fuel injected on the operation characteristics of the two-stroke engine. The fuel choice of kerosene is highly appreciable as data with kerosene is limited. Overall, the result seems promising and may be of interest to some readers.
I would like to suggest the following points to the authors that could increase the readability of the manuscript,
1. A table with a comparison of fuel properties between kerosene (the one used in this study) and gasoline could strengthen the arguments on variation in the combustion characteristics between these two fuels.
2. In addition to average values, it is suggested to include the standard deviation wherever possible. This could help in further understanding the stability of the engine.
3. On line 162, it's been mentioned that “the front of the flame is large”, authors should clarify how they arrived at this conclusion.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Autors describe in Chapter 3.2 an experimental prototype of the modified engine with instrumentation system and control software added. However, it is not clear if this hardware setup was used for production of any real (not simulated) experimental data? If not, what is the reason? An explanation should be added.
The hardware prototype could be used for instance for validation of the simulation data, this would improve the quality of the paper.
Additional minor remarks:
Figure 14 caption (line 236) should include "NO" expression instead of "No".
Figures 28 to 31 - it is not clear if they contain simulation data or measurement results, please improve the description.
Final conclusion (lines 381 and 382) could be slightly modified by adding infomation that these recommendations are valid for that particular engine configuration. Is it possible for Authors to include more general suggestions for parameter settings regarding different engine configuration?
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
