FY2015 Annual Report for Alternative Fuels DISI Engine Research.

Sj??berg, Carl-Magnus G.¹ 

[1] Sandia National Lab. (SNL-CA), Livermore, CA (United States)

DOI  :  10.2172/1235214
RP-ID  :  SAND--2016-0241R
PID  :  OSTI ID: 1235214
Others  :  Other: 618367

学科分类：燃料技术

美国|英语

来源: SciTech Connect

【 摘 要 】

Climate change and the need to secure energy supplies are two reasons for a growing interest in engine efficiency and alternative fuels. This project contributes to the science-base needed by industry to develop highly efficient DISI engines that also beneficially exploit the different properties of alternative fuels. Our emphasis is on lean operation, which can provide higher efficiencies than traditional non-dilute stoichiometric operation. Since lean operation can lead to issues with ignition stability, slow flame propagation and low combustion efficiency, we focus on techniques that can overcome these challenges. Specifically, fuel stratification is used to ensure ignition and completeness of combustion but has soot- and NOx- emissions challenges. For ultralean well-mixed operation, turbulent deflagration can be combined with controlled end-gas auto-ignition to render mixed-mode combustion that facilitates high combustion efficiency. However, the response of both combustion and exhaust emissions to these techniques depends on the fuel properties. Therefore, to achieve optimal fuel-economy gains, the engine combustion-control strategies must be adapted to the fuel being utilized.