Numerical study of the effect of split direct injection on the lean-burn combustion characteristics in a poppet-valve two-stroke gasoline engine at high loads
| Autor: | Bang-Quan He, Hua Zhao, Xiao Li |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
020209 energy
Mechanical Engineering Poppet valve Aerospace Engineering Ocean Engineering 02 engineering and technology Combustion Fuel injection Automotive engineering law.invention 020401 chemical engineering law Automotive Engineering 0202 electrical engineering electronic engineering information engineering Environmental science 0204 chemical engineering Engine knocking Gasoline Two-stroke engine Lean burn Petrol engine |
| Zdroj: | International Journal of Engine Research. 22:1776-1793 |
| ISSN: | 2041-3149 1468-0874 |
| DOI: | 10.1177/1468087420932409 |
| Popis: | Poppet-valve two-stroke gasoline engines can increase specific power of four-stroke gasoline engines with the same displacement. But knocking combustion may also occur at high loads in two-stroke engines. The application of stratified lean-burn on poppet-valve two-stroke gasoline engines can avoid knocking and increase combustion stability. To investigate the effect of the mixture stratification on lean-burn events at high loads, simulation was conducted in different split direct injection conditions with constant fuel mass when equivalence ratio is 0.625. Results show that most fuel distributes near the center of the cylinder at any second direct injection ratio ( rSOI2). At different rSOI2s, auto-ignition occurs during flame propagation, causing shortened combustion duration. Auto-ignition causes the second peak of the heat release rate. The second peak of the heat release rate first decreases and then increases with increased rSOI2. Indicated mean effective pressure and indicated thermal efficiency increase with increased maximum pressure rise rate. The maximum indicated thermal efficiency of 42% can be reached without knocking combustion at 1500 rpm. The proportion of fuel mass through auto-ignition in the cylinder is an important factor to change the indicated thermal efficiency of a lean-burn engine at high loads. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|