TY - JOUR
T1 - Post-oxidation phenomena enhancement with scavenging and secondary air injection in exhaust manifold of a turbocharged GDI engine
AU - Kumar, Madan
AU - Moriyoshi, Yasuo
AU - Kuboyama, Tatsuya
N1 - Publisher Copyright:
© IMechE 2022.
PY - 2023/6
Y1 - 2023/6
N2 - A detailed investigation of post-oxidation phenomena by individual and combined effects of scavenging (VVT tuning) and secondary air injection (SAI) was performed. The 1-D simulation including a post-oxidation model developed by Stuttgart University as an international collaboration was used for investigation which includes the main exhaust gas species as CO, H2, and O2-based chemical reactions. Then, experimental validation was conducted on a 4-cylinder turbocharged gasoline direct injection (GDI) engine. From the results, it was noted that the post-oxidation can be actuated at limited operating conditions as higher overlap in moderated speed and load only when scavenging phenomena are considered. However, at lower overlap, it is restricted due to lower O2 scavenging even though the exhaust temperature meets the post-oxidation requirement. Also, the in-homogeneity observed at higher overlap that restricts the significant post-oxidation before the turbocharger upstream. On the other hand, the SAI mechanism can actuate the post-oxidation even at lower overlap if enough O2 concentration, exhaust temperature, and adequate mixing are attained. Hence, the post-oxidation zone can be extended to lower speed-load and overlap if both parameters as scavenging and SAI introduced together. This can possibly lead to better turbo-performance along with lower emissions. However, thermal efficiency needs to be compromised to some extent. It was also found that the effective post-oxidation can be actuated by SAI compared to scavenging-based phenomena if the same concentration of the O2 and temperature are maintained by both mechanisms. This appeared due to the fresh air continuously injected at the exhaust port even at the time of exhaust valve opening duration in SAI mechanism that allows the better mixing of O2 and hot unburned gas species. However, in scavenging-based phenomena, firstly, hot unburned gas passed through the exhaust manifold and then scavenged air follows which restricts mixing between scavenged air and unburned gas species.
AB - A detailed investigation of post-oxidation phenomena by individual and combined effects of scavenging (VVT tuning) and secondary air injection (SAI) was performed. The 1-D simulation including a post-oxidation model developed by Stuttgart University as an international collaboration was used for investigation which includes the main exhaust gas species as CO, H2, and O2-based chemical reactions. Then, experimental validation was conducted on a 4-cylinder turbocharged gasoline direct injection (GDI) engine. From the results, it was noted that the post-oxidation can be actuated at limited operating conditions as higher overlap in moderated speed and load only when scavenging phenomena are considered. However, at lower overlap, it is restricted due to lower O2 scavenging even though the exhaust temperature meets the post-oxidation requirement. Also, the in-homogeneity observed at higher overlap that restricts the significant post-oxidation before the turbocharger upstream. On the other hand, the SAI mechanism can actuate the post-oxidation even at lower overlap if enough O2 concentration, exhaust temperature, and adequate mixing are attained. Hence, the post-oxidation zone can be extended to lower speed-load and overlap if both parameters as scavenging and SAI introduced together. This can possibly lead to better turbo-performance along with lower emissions. However, thermal efficiency needs to be compromised to some extent. It was also found that the effective post-oxidation can be actuated by SAI compared to scavenging-based phenomena if the same concentration of the O2 and temperature are maintained by both mechanisms. This appeared due to the fresh air continuously injected at the exhaust port even at the time of exhaust valve opening duration in SAI mechanism that allows the better mixing of O2 and hot unburned gas species. However, in scavenging-based phenomena, firstly, hot unburned gas passed through the exhaust manifold and then scavenged air follows which restricts mixing between scavenged air and unburned gas species.
KW - Scavenging
KW - emissions
KW - post-oxidation
KW - secondary air injection
KW - turbo-performance
UR - http://www.scopus.com/inward/record.url?scp=85138284127&partnerID=8YFLogxK
U2 - 10.1177/14680874221118870
DO - 10.1177/14680874221118870
M3 - 文章
AN - SCOPUS:85138284127
SN - 1468-0874
VL - 24
SP - 2388
EP - 2409
JO - International Journal of Engine Research
JF - International Journal of Engine Research
IS - 6
ER -