An attempt to implement partially premixed combustion strategy in a multi-cylinder CRDI engine: A detailed experimental and wavelet transform analysis

An experimental investigation into the combustion stability and emissions of an n-butanol/diesel blended fueled partially premixed compression ignition (PPCI) engine

“…This might be due to the higher LHE and RON of n-butanol, which delayed the SOC timing and increased the ignition duration of DB40 and DB20 fuel in contrast to diesel fuel. 11 Compared to earlier injection timings, DB40 fuel achieved the highest peak of premixed HRR at 4° CA BTDC SOI timing, as shown in Figure 2(a) and (b). Additionally, CA50 and peak of HRR are to be found advanced at early injection timing of 12° CA BTDC compared to late SOI timing of 4° CA BTDC, as displayed in Figure 12 in Supplemental Appendix A1 and Figure 2(b).…”

“…DB40 and DB20 fuels have a higher ignition delay than DB00 fuels, resulting in a maximum HRR peak far away from the top dead center and lower cylinder temperatures at 2 bar BMEP load under late injection timing of 4° CA BTDC. 11 This is the possible reason for the higher CCVs of DB20 and DB40 than DB00 fuel.…”

“…At the early SOI timing of 12° CA BTDC, combustion begins during the compression stroke, and the piston moves toward the top dead center, raising cylinder pressure together with the heat released by the combustion process, resulting in the increased temperature for all tested fuels. 11 Solaka et al and coworkers employed the method of fitting a Gaussian profile to the rising flank of the premixed peak between half of the maximum and the actual peak to calculate the premixed combustion ratio, which is based on the heat released during the premixed combustion phase divided by the total heat released. 35 Figure 12 in Supplemental Appendix A1 depicts that a high premixed combustion ratio is obtained with a late injection timing of 4° CA BTDC because combustion occurs mainly during the expansion stroke.…”

“…In contrast to D00 and DB20 fuel, DB40 fuel has less LHV, resulting in a delayed combustion phase and end of injection (EOI). 11 As a result, DB40 exhibits considerable cyclic variability for both early and late SOI timing settings. This suggests that the start of injection timing and n-butanol/diesel blended fuels significantly impact on the CCVs of diesel engines and that increased CCVs limit the usage of too late injection timing or a high n-butanol ratio.…”

“…homogeneous charge compression ignition (HCCI), partially premixed combustion (PPC), premixed charge compression ignition (PCCI), and reactivity controlled compression ignition (RCCI)) by employing renewable high research octane number (RON) fuel and various tools such as RSM, WPS, 0-1, etc. [7][8][9][10][11] It has been demonstrated in several studies that LTC combustion techniques combined with renewable higher RON fuel could achieve high BTE while producing ultra-low NO X levels and smoke in most CI engines under most operating conditions. 2,[11][12][13] The researchers discovered that higher alcohol levels in biodiesel reduced density and ignition quality, but BTE improved by 30% with 8.9% biodiesel blending.…”