Effects of gliding arc plasma on ignition and extinction flame evolution in combustors under low pressure conditions

低气压条件下滑动弧等离子体对燃烧室点熄火特性的影响

¹ Mechanical and Electrical Engineering College, Xi'an Polytechnic University, Xi'an 710600, China
² National Key Lab of Aerospace Power System and Plasma Technology, School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an 710049, China
³ National Key Lab of Aerospace Power System and Plasma Technology, School of Aviation Engineering, Air Force Engineering University, Xi'an 710038, China
⁴ School of Aerospace Engineering, Xi'an Jiaotong University, Xi'an 710049, China
⁵ School of Aero-Engine, Shenyang Aerospace University, Shenyang 110136, China

Received: 7 May 2025

Abstract

To address the issues of ignition and flame extinction in the combustion chamber of a small turbine engine under high-altitude and low-pressure conditions, a gliding arc plasma-assisted ignition and combustion dome was integrated into the combustor. Based on a low-pressure combustion test platform, experiments were conducted to characterize low-pressure discharge dynamics, ignition performance, and flame extinction performance. Systematic comparisons were performed on discharge characteristics, flame evolution processes, and lean-blowout boundaries across varying pressures. Results show that at 80 kPa and 300 L/min, the plasma-assisted ignition and combustion dome exhibited reduced electrical parameters: peak-to-peak voltage decreased to 2 kV, maximum peak voltage to 5 kV, and discharge cycle to 2.2 ms, average discharge power increases to 137 W (90 kPa) and then decreases to 111.6 W(75 kPa) comparing with that via atmospheric operation. Gliding arc plasma significantly broadened the ignition and flameout limits, achieving a 13.5% expansion in ignition limits and a 40.4% reduction in ignition delay time relative to conventional spark ignition. Furthermore, at 90 kPa, the flameout limit was extended by 16.4%. The present study provides the critical insights into plasma-assisted ignition and combustion mechanisms under low-pressure conditions, advancing the design of reliable combustion systems for high-altitude aerospace applications.

摘要

针对高空低气压环境下, 小型涡扇发动机燃烧室面临的点火及熄火等问题, 基于一款小型涡扇发动机滑动弧等离子体点火助燃头部, 依托低压基础燃烧实验平台, 开展了低气压放电、点火和熄火实验。着重对比分析了不同空气压力下点火助燃头部放电特性、燃烧室点火、熄火火焰演化过程及边界等影响规律。结果表明: 在80 kPa、300 L/min条件下, 相较于常压点火助燃头部电压峰-峰值、最大峰-峰值电压与周期分别减小至2 kV, 5 kV和2.2 ms, 平均放电功率先增大至137 W(90 kPa)而后减小至111.6 W(75 kPa); 施加等离子体激励可以显著拓宽点熄火边界, 缩短点火延迟时间。相较于常规电火花点火, 点火边界拓宽13.5%, 点火延迟时间缩短40.4%。在90 kPa条件下其熄火边界相较于常规熄火拓宽16.4%。