Investigation of compression temperature in highly charged spark-ignition engines

Abstract

One of the critical parameters for the occurrence of spark-knock and pre-ignition of highly charged spark-ignition (SI) engines is the compression temperature. The investigation of the compression temperature and a better understanding of the combustion behaviour inside the combustion chamber are of great importance for avoiding these phenomena and also for further downsizing of engines. Pure rotational coherent anti-Stokes Raman spectroscopy (RCARS) is an innovative tool providing information on the compression temperature by using only two small line-of-sight optical accesses on the cylinder wall. In this work, RCARS measurements were performed in motored and fired operation, and the results obtained from RCARS spectra have been used in combination with isentropic calculations to improve the accuracy of the compression temperature determination. Studies on the compression temperature by the variation of the intake temperature, the engine load, and the fuel were conducted and the influence of evaporation enthalpy on the compression temperature is discussed.

Simulation Analysis of Combustion Parameters and Emission Characteristics of CNG Fueled HCCI Engine

“…The timing of autoignition of HCCI combustion is determined by the cylinder charge conditions, rather than the spark timing or the fuel injection timing that are used to initiate combustion in the SI and CI engines, respectively [3]. As demonstrated by many experimental results [4,5], controlled autoignition requires regulation of the charge properties, namely, temperature, pressure, and composition at the intake valve closing [IVC]. The numerical approach has significant potential to investigate the HCCI engine combustion phasing, start of combustion (SOC), and emission characteristics [6][7][8].…”

High temperature O2 vibrational CARS thermometry applied to a turbulent oxy‐fuel combustion process

“…In recent years, it was applied, e.g. to internal combustion engines, high pressure burners or gas turbines . Also, large technically relevant flames were investigated like a full‐scale coal furnace or a sooting turbulent pool fire .…”

Simultaneous measurements of fuel vapor concentration and temperature in a flash‐boiling propane jet using laser‐induced gratings

“…For spray characterization, a lot of different diagnostic techniques have been developed in the past and are now nearly routinely used. To determine the gas temperature, optical methods including laser‐induced fluorescence (LIF) and pure rotational coherent anti‐Stokes Raman spectroscopy have been developed. The local fuel/air ratio can be measured using, e.g.…”