Abstract
Lately, new regulations regarding harmful exhaust gases and fuel economy have been enforced. Main focus of research has been on the reduction of exhaust gases and improvement of fuel economy. In order to achieve the above objective, the alternative fuel as well as lean burn combustion were used.
Lean burn combustion has many problems mainly related to the unstable combustion conditions, as a result of the ignitability defect, low pressure and heat loss due to combustion period expanding. For that reason spark ignition process, air fuel mixture flow and satisfied charge of combustion chamber need to be improved. The major factor of designing lean burn combustion engine is to prevent misfire.
When air fuel ratio is over 20:1, misfire in the cylinder, non-uniform combustion and vibration are responsible for the deteriorated engine output.
Recently research has focused on the ultra lean burn combustion engine as it produces misfire. The reason for that is the increase in the air to air fuel mixture ratio, which is adjusted from 30:1 to 50:1. To solve this problem, spark plug of traditional engine should be improved. Further more the location should be adjusted.
This research analyses a method of combustion, when stratified charge is ignited with LPG. Further more we investigated the combustion field using Excimer Laser, thermocouple and RTD probes which is self-manufactured. As a result, the results present the optimum condition of ultra lean burn combustion characteristics.