Engine Efficiency Measurements Using a 100 kHz Radio Frequency Corona Igniter

Abstract

<div class="section abstract"><div class="htmlview paragraph">Conventional spark-ignition engines are currently incapable of meeting rising customer performance demands while complying with even stringent pollutant-emissions regulations. As a result, innovative ignition systems are being developed to accomplish these targets. Radio-Frequency corona igniters stand out for their ability to accelerate early flame growth speed by exploiting the combined action of kinetic, thermal and transport effects. Furthermore, a volumetric discharge enables the promotion of combustion over a wide area, as opposed to the local ignition of traditional spark.</div><div class="htmlview paragraph">The present work wants to evaluate the advantages of a Streamer-type Radio Frequency corona discharge at about 100 kHz with respect to those of traditional spark igniter. To explore the corona ignition behavior, experimental campaigns were performed on a three-cylinder spark-ignition engine fueled with gasoline, at condition of stochiometric mixture, low speed, two different loads and by varying the igniter control parameters, i.e. driving voltage and activation time. The igniters’ performance was investigated using indicating and efficiency analysis. The latter was accomplished by estimating engine fuel consumption and the delivered engine torque.</div><div class="htmlview paragraph">When compared to traditional spark, the corona device showed substantial enhancement of the effective efficiency up to 2%, with improvement of delivered torque of about 10%, and combustion stability up to 40%.</div></div>