Environmental Science and Pollution Research

, Volume 26, Issue 18, pp 18291–18303 | Cite as

Numerical evaluation of pollutant emissions of a two-stroke linear engine

  • Chenheng YuanEmail author
  • Pengbo Zhang
  • Yang Liu
Research Article


Combustion engines bring a lot of pollution products to human living environment. This study introduced a green engine called free-piston linear engine (FPLE), and performed an evaluation on the pollutant emissions of a diesel FPLE by comparison with a corresponding conventional crankshaft engine (CCE). The combustion reaction and pollutant formation were described by a comprehensive model which considers the special operation mechanism of the FPLE. The effect of dynamic and fuel quantity on the unclean combustion products of the FPLE and the CCE was compared. Results indicate that in the case of the fuel quantity of 7.1 mg condition, the pollutant forming in the FPLE is generally later than that in CCE because of the higher speed of FPLE around the reverse point of stroke, and a significant advantage in nitric oxide (NO) emission is found for the FPLE, although it emits more carbon monoxide (CO) and soot. Moreover, compared with the CCE, the FPLE is cleaner in lean fuel conditions because the NO production of the FPLE is only half of that of the CCE, and that of other pollutants is almost at the same level. However, in heavy fuel conditions, the FPLE shows a disadvantage in CO and soot emission due to the serious afterburning effect and poor oxygen environment in some local areas, although its NO production is still lower than that of the CCE.


Linear engine Pollutants Comparative evaluation Piston motion Fuel quantity 



We express sincere gratitude to the sponsors.


This research was sponsored by the National Natural Science Foundation of China (Grant No. 51805056), the Open Foundation of Chongqing Key Laboratory of “Human-Vehicle-Road” Cooperation & Safety for Mountain Complex Environment (Grant No. 2018HVRC03), and the Open Foundation of Key Laboratory of Advanced Manufacture Technology for Automobile Parts (Chongqing University of Technology), Ministry of Education (Grant No. 2018KLMT02).


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Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2019

Authors and Affiliations

  1. 1.College of Traffic & TransportationChongqing Jiaotong UniversityChongqingChina
  2. 2.Key Laboratory of Advanced Manufacture Technology for Automobile Parts (Ministry of Education)Chongqing University of TechnologyChongqingChina
  3. 3.Chongqing Key Laboratory of “Human-Vehicle-Road” Cooperation & Safety for Mountain Complex EnvironmentChongqingChina

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