Spatial and time resolved determination of the vibrational temperature in ignition sparks by variation of the dwell time

Abstract

The ignition process initiates the combustion in spark-ignition engines. Therefore, understanding the ignition process is an important aspect in developing more efficient combustion engines. In this thesis, the vibrational temperature of an ignition spark in air under atmospheric pressure and room temperature is observed in spatial and temporal resolution. The temperature is determined by comparing simulated spectra with the measured spectra of the second positive system of N 2 between 360 and 381 nm. Changing the dwell time had no significant effect on the vibrational temperature of the three spark phases. In the breakdown the vibrational temperature is about 3300 K. The vibrational temperature of the following arc discharge is in the range of 3750 K to 4350 K. The glow discharge is divided into the negative glow and the positive column. Both show similar vibration temperatures in the range of 3500 K to 3900 K.

Rotational and vibrational temperatures of transient atmospheric glow plasma

“…The position of the measurement within the plasma was not specified and the result is for a short, pulsed plasma. Michler [11,12] reported temperature values for a sparkplug geometry of a pulsed plasma for glow and arc discharge with spatial dimensions. The results showed that the rotational temperature increased near the anode but was also significantly higher near the cathode.…”