Rotating gliding arc discharge plasma-assisted combustion from ignition hole
Introduction
Aero-engines are continuously being developed around the world. To greatly improve the thrust–weight ratio and the power–mass ratio, the combustors of military aero-engines have been developed with large temperature increases [1]. As a popular technology of high-energy ignition and combustion enhancement, plasma-assisted combustion (PAC) [2], [3], [4], [5] can increase the quantity of active chemical components in the combustion chamber and improve the chemical reaction rate, which can solve the instability problem of flame combustion [6], [7], [8], [9].
PAC technology, as a popular assisted-combustion technology for supersonic combustion [10], [11], [12], [13], [14], has attracted the attention of many countries, and scholars have carried out considerable research in recent years. Bulat et al. [15] studied plasma-assisted ignition and combustion of fuel/air mixtures in low- and high-speed flows. The research showed that the streamer discharge could create multiple ignition points compared to a regular igniter and provide almost instantaneous ignition of the entire volume of the mixture. The air/propane mixture is ignited by the sub-critical discharge and burns steadily in low- and high-speed flows (flow speed varies from 10 to 500 m/s) assisted by the plasma. Kim et al. [16] found that CO and NOx emissions were significantly reduced when non-thermal plasma (NTP) was added, which was attributed to the enhanced combustion by the streamers or the ozone produced by the dielectric barrier discharge (DBD) reactor. Mardani et al. [17] used non-equilibrium plasma discharges to achieve moderate or intense low-oxygen dilution (MILD) combustion. It was found that the plasma not only increased the flame length but also increased the reaction intensity by a factor of 3.
Considerable research has been carried out in the field of plasma-assisted combustion in China. He et al. [18] calculated and analyzed the chemical reaction mechanism of the plasma ignition process, showing that O atoms, H atoms, and CH groups could significantly shorten the ignition delay time of kerosene/air mixtures, and the greater the particle mole fraction, the more significant the influence on the ignition delay time. Chen et al. [19] studied the main elementary reactions of plasma-assisted methane combustion. Those excited state species produced by the plasma discharge promoted the reaction potential energy, reduced the activation energy, and accelerated the reaction process. Chen et al. carried out an in-depth study on the gliding arc discharge plasma and proposed three configurations to implement PAC in the combustion chamber: assisted combustion from primary holes (ACPH), assisted combustion from dilution holes (ACDH), and assisted combustion in front of the combustor diffuser (ACCD) [20], [21]. All these plans improve the combustion performance to some extent, but each has room for optimization.
In recent years, gliding arc discharge plasma has received growing attention compared to dielectric barrier discharge and nanosecond pulse discharge [22], [23], [24], because gliding arc discharge possesses the merits of both non-thermal and thermal plasmas [25]. In addition, the gliding arc discharge plasma device is relatively simple compared with other discharge forms, which shows its potential for large-scale industrial applications in the future [26]. At present, scholars in China are focusing on the mechanism of PAC and have developed many kinds of plasma actuators [27], [28]. However, there are still many difficulties in applying the actuator to real aero-engines. To explore the feasibility of applying the actuator to the combustion chamber, a new type of plasma-assisted combustion actuator that does not depend on the external air supply was designed in this paper. On this basis, a new assisted-combustion plan called assisted combustion from the ignition hole (ACIH) was proposed and compared with the ACPH and ACDH. Finally, the ACIH was validated by experiments in a two-head annular combustor.
Section snippets
Experimental platform of plasma-assisted combustion
The experimental system consisted of an actuator, air compressor, air heating system, oil supply system, plasma excitation power supply, and data acquisition and analysis system. The sketch of the whole experimental setup is shown in Fig. 1. The photos of the local experimental system are shown in Fig. 2.
Experiments were carried out on a fan-shaped test piece that was cut from a real aero-engine annular combustion chamber. This ensured that the combustion flow in the experimental section was
Design of assisted-combustion plan
The installation configurations of the two types of actuators are presented in Fig. 8. Compared to the traditional PACA, the SPACA was installed on the head of the combustion chamber and replaced the original igniter. With this installation scheme, the SPACA could use the secondary stream of the combustion chamber as the air supply of the discharge. More importantly, it did not significantly change the original structure of the combustion chamber. On the exterior, it did not affect the assembly
Discharge characteristics of actuator
The typical voltage and current waveform of the actuator measured by the voltage probe (Tektronix P6015A) and current probe (Tektronix TCP0030) in the experiment are shown in Fig. 10. The discharge voltage waveform was similar to a sine wave during arc gliding. At the times indicated by the arrows in the figure, unidirectional breakdown occurred during the gliding arc discharge. There are metastable molecules in the active particles generated by the discharge process, and the breakdown voltage
Conclusion
In this paper, a self-induced gas-plasma-assisted combustion actuator (SPACA) was designed. A fan-shaped test piece platform was developed to examine the improvement effect on the combustion chamber performance using the SPACA. A new plasma-assisted combustion configuration was proposed for the first time, i.e., assisted combustion from the ignition hole (ACIH). The average outlet temperature , uniformity of the outlet temperature field, combustion efficiency, and lean blowout performance
CRediT authorship contribution statement
Li Fei: Conceptualization, Methodology, Validation, Writing - original draft. Bing-Bing Zhao: Project administration, Writing - review & editing. Yi Chen: Methodology, Data curation, Formal analysis, Software. Li-Ming He: Funding acquisition, Resources. Zi-Chen Zhao: Software, Formal analysis. Jian-Ping Lei: Software, Formal analysis.
Declaration of Competing Interest
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
Acknowledgement
This research was supported by the National Natural Science Foundation of China (Funding Nos. 51806245 and51436008).
References (41)
- et al.
Plasma-assisted ignition and combustion
Prog. Energy Combust. Sci.
(2013) - et al.
Plasma assisted combustion: dynamics and chemistry
Prog. Energy Combust. Sci.
(2015) - et al.
Experimental investigation on the impacts of ignition energy and position on ignition processes in supersonic flows by laser induced plasma
Acta Astronaut.
(2017) - et al.
Numerical assessment of MILD combustion enhancement through plasma actuator
Energy
(2019) - et al.
Main reaction paths or channels of plasma assisted methane combustion
J. Combust. Sci. Technol.
(2018) - et al.
Experimental study of rotating gliding arc discharge plasma-assisted combustion in an aero-engine combustion chamber
Chin. J. Aeronaut.
(2019) - et al.
Experimental study of dielectric barrier discharge plasma-assisted combustion in an aero-engine combustor
Aerosp. Sci. Technol.
(2020) - et al.
Dissociation of H2S in non-equilibrium gliding arc “Tornado” discharge
Int. J. Hydrogen Energy
(2009) - et al.
Heat generation mechanisms of DBD plasma actuators[J]
Exp. Therm. Fluid Sci.
(2018) - et al.
Experimental study on thermal ignition and combustion of droplet of ammonium dinitramide based liquid propellant in different oxidizing gas atmospheres
Acta Astronaut.
(2020)
Experimental investigation on the gliding arc plasma supported combustion in the scramjet combustor
Acta Astronaut.
Experimental investigation of multichannel plasma igniter in a supersonic model combustor[J]
Exp. Therm. Fluid Sci.
Gas Turbine Combust
Parametric study of plasma-assisted ignition in combustible mixtures
AIAA Aerospace Sciences Meeting
Computational simulation of nanosecond pulsed discharge for plasma assisted ignition
J. Phys. Conf. Ser.
Challenges in understanding and predictive model development of plasma-assisted combustion
Plasma Phys. Controlled Fusion
Molecular beam studies of elementary reactions relevant in plasma/combustion chemistry: O(3P) + unsaturated hydrocarbons
J Rendiconti Lincei Scienze Fisiche E Naturali
Experimental study of influence on microwave plasma ignition combustion performance of pulse microwave signals
IEEE Access
Cited by (2)
Characteristics of an AC rotating gliding arc discharge in NH<inf>3</inf> and air atmospheres
2024, Physics of PlasmasResearch progress on non-equilibrium plasma-assisted ignition and combustion
2022, Hangkong Dongli Xuebao/Journal of Aerospace Power