PCCI engines can reduce NOx and PM emissions simultaneously without sacrificing thermal efficiency, but a low combustion temperature resulting from early fuel injection, and ignition occurring prior to TDC, can cause higher THC and CO emissions and fuel consumption. In conclusion, it was found that the PCCI combustion achieved by the 2-stage injection strategy with optimized calibration factors...

Thermal radiation properties of turbulent premixed flames have received little attention in the past perhaps because of the lower radiative heat loss compared with that for non-premixed flames. However, the high-temperature sensitivity of NO kinetics and the importance of radiation in near-limit laminar premixed flames provide fundamental reasons for studies of radiation properties of turbulent...

EXPERIMENTAL INVESTIGATION AND DEVELOPMENT OF ANEXTENDED TWO COLOR METHOD (eTCM) WITH APPLICATION TO INTERNALCOMBUSTION ENGINESbyELENA FLOREAAugust 2013Advisor: Dr. Dinu TarazaMajor: Mechanical EngineeringDegree: Doctor of Philosophy The internal combustion engine is on a continuous path of improvement toreduce exhaust gaseous emissions and improve fuel econo...

Even if the goal of reducing NOx emissions pushes towards the use of premixed combustion, moderately swirling turbulent non-premixed flames are still widely employed in both industrial furnaces and gas turbines, because of their stable and safe behaviour in a wide range of fuels and operating conditions. Computational Fluid Dynamics (CFD) has become in recent years a key tool for the design of ...

Amajor goal of combustion research is to develop accurate, tractable, predictive models for the phenomena occurring in combustion devices, which predominantly involve turbulent flows. With the focus on gasphase, non-premixed flames, recent progress is reviewed, and the significant remaining challenges facing models of turbulent combustion are examined. The principal challenges are posed by the ...

A rapid compression machine (RCM) has been designed and built for investigating the autoignition characteristics of bio-derived jet and diesel fuels. The RCM has been designed with a particular emphasis on versatility, so that non-volatile fuels may be tested in a premixed gas phase, as a fuel spray, or as an aerosol in an oxidizing bath gas. A blend of these test approaches provides insight in...

1 Introduction A balance between the flame propagation speed and the fluid velocity must be maintained to maintain the flame in a chemically reacting flow. Since the fluid velocity exceeds the flame speed in supersonic combustion applications, the flameholding issue is solved by generation of some sort of recirculation region which ensures sufficient residence time so that the processes involve...

The upstream interaction of twin premixed hydrogen-air flames in 2-D turbulence is studied using direct numerical simulations with detailed chemistry. The primary objective is to determine the effect of flame stretch on the overall burning rate during various stages of the interaction. Preferential diffusion effects are accounted for by varying the equivalence ratio from symmetric rich-rich to ...

Abstract—This study is aiming at establishing the relationship between the optical signal of flame and an equivalent ratio of flame. In this experiment, flame optical signal in a furnace is measured using photodiode. The combustion system is composed of metal fiber burner and vertical furnace, and flame chemiluminescence is measured at various experimental conditions. In this study, the flame c...