Week-4 : Basic Calibration of Single cylinder CI-Engine
1. SI vs CI
SI
CI
- In CI engine fuel is diectly injected to cylinder while in SI engine fuel is injected via inlet port 1
- In CI engine compression ratio is b/w 16.5-19 & SI engine compression ratio is b/w 9.5-12.
- SI engine fuel properties
CI engine fuel properties
2.
| SI | CI | |||
| BSFC [g/kW-h] | 241.8 | BSFC [g/kW-h] | 208.7 | |
| A/F Ratio | 14.51 | A/F Ratio | 20.77 | |
| Exhaust Temperature [K] | 1209 | Exhaust Temperature [K] | 1418 |
3.
MFB 50 and impact on performance
| Performance | ||||
| MFB-NORMAL | MFB=50% | %CHANGE | ||
| Engine Speed (end of cycle) | RPM | 3600 | 3600 | |
| IMEP720 - Net Indicated Mean Effective Pressure | bar | 17.585403 | 7.785842 | -55.73 |
| IMEP360 - Gross Indicated Mean Effective Pressure | bar | 18.853579 | 8.992245 | -52.30 |
| PMEP - Pumping Mean Effective Pressure | bar | -1.2681746 | -1.2064031 | -4.87 |
| ISFC - Indicated Specific Fuel Consumption | g/kW-h | 208.52122 | 470.95374 | 125.85 |
| PMEP Adjusted (Shelby definition) | bar | -1.3255929 | -1.2018172 | -9.34 |
| IMEP Adjusted (Shelby definition) | bar | 18.910997 | 8.987659 | -52.47 |
| Intersection Pumping Integral | bar | -0.97497463 | -1.0881472 | 11.61 |
| Intersection Gas Exchange Efficiency | fraction | 0.9474834 | 0.87742966 | -7.39 |
| Intersection Power Integral | bar | 18.565083 | 8.877735 | -52.18 |
| Incremental Compression Work | bar | 0.017226303 | 0.017570151 | 2.00 |
| EVO Loss | bar | 0.040191986 | -0.0221562 | -155.13 |