Experimental investigation for influences of electrode location and area on ionic current

Five electrodes with different areas were installed at different locations of the constant volume combustion bomb. Ionic current during combustion was obtained by the combination of different measuring electrodes. The influences of electrode location and area on ionic current were analyzed according to ionic current signals, pressure signals and schlieren pictures. The experiments show that the electrode location can affect starting timing, value, peak, peak timing, etc. of ionic current. When the anode keeps constant, the number of rising signals of ionic current increases with the number of cathode, revealing that partial combustion information in the vicinity of the electrode can be extracted from ionic current. The charge absorbed by electrodes increases with the increasing anode and cathode areas. Therefore, ionic current increases with the increasing anode and cathode areas, and cathode area exerts a greater effect on ionic current than anode area, which provides a theoretical basis for application of ionic current method to measuring combustion conditions of engine.