Experimental investigation on ignition characteristics of multichannel jet enhanced plasma igniter under high altitude extreme conditions

Enhancing the ignition system performance of turbo engines is crucial, with a focus on rapidly and reliably igniting the entire combustor in low-temperature, low-pressure, high-speed inlet flow conditions. This challenge has garnered international attention. To address the issue of reliable ignition in the combustors of advanced propulsion system, this paper proposes a Multichannel Jet Enhanced Plasma Igniter (MJEPI) and conducts comparative experimental studies with the conventional spark igniter in a component-level dual-dome swirl combustor. The ignition limit in the combustor is obtained and the ignition processes are recorded. Experimental results demonstrate that the MJEPI significantly improves the ignition performance at high altitude. Specifically, at 0 km and 6 km for ground start-up, ignition limit is extended by 36% and 29%, respectively. At 6 km and 12 km for high-altitude relight, ignition limit is extended by 32% and 21%, respectively. The maximum ignition height is increased by 2.3 km, as determined by the global equivalence ratio of 1. The primary reason for these improvements is attributed to the larger initial flame kernel with greater penetration depth generated by MJEPI, which enables it to withstand more sever conditions such as low temperature, low pressure, and poor kerosene spray quality at elevated altitudes.