Kalorimetrie der drei Entladungsformen des elektrischen Zündfunkens

Development of a method for experimental investigation of combustion process in lean burn gas engines

“…The experimental investigation of heat losses during the transmission of energy from the spark discharge at the spark plug (SP) electrodes to the surrounding compressed air gas medium has been described in [9]. However, no experimental data on heat transfer from the discharge at the SP electrodes to the gas medium under the gas engine operating conditions have been found, although the results of [9] can be used in an experiment on a gas engine.…”

“…The discharge power and heat transfer of the discharge energy to the surrounding gas medium depend on the type of discharge [7,9,11]. By definition, the discharge type determined by the mechanism of emission the main charge carriers from the material of the electrodes into the gas medium [7,15].…”

Spark Heat Transfer Measurements in Flowing Gases

“…The energy transfer efficiencies measured without flow are considerably higher than those reported previously. For example, Teets and Sell [14] measured, using calorimetric techniques, an efficiency of 13 ± 2% for a "standard" spark plug with 2 mm gap, and Saggau [15] gives an efficiency value of about 13% for 2.5 mm diameter stainless steel electrodes with a 2 mm gap. We measured an efficiency of 26% for 2 mm diameter, 2 mm gap electrodes.…”

“…A more accurate determination of these efficiencies, particularly the arc phase one, would require a larger number of measurements. Saggau [15] gives an efficiency value of 38% for a 2 mJ arc discharge under similar conditions without flow. For modelling purposes, as a first approximation, the energy input (vs. time) from the spark to the gas can be characterised by a curve like that of Figure 3: an input of h arc E arc over a period of several microseconds followed by a period lasting t milliseconds with a constant power equal to (h gl E gl )/t.…”

“…This information is usually obtained from published experimental data [14] and [15] measured by calorimetric techniques [16,17,18]. A drawback of these techniques is that it is not possible to study with them the spark efficiency in a flowing gas.…”