First applications of ultrasound technology in solid rocket propellant combustion promotion

Zhan Wen; Heng Jing; Feng Hao; Yuheng Wang; Bicheng Kuang; Peijin Liu; Wen Ao

doi:10.1016/j.ultsonch.2024.107107

First applications of ultrasound technology in solid rocket propellant combustion promotion

Ultrason Sonochem. 2024 Oct 15:111:107107. doi: 10.1016/j.ultsonch.2024.107107. Online ahead of print.

Authors

Zhan Wen¹, Heng Jing¹, Feng Hao², Yuheng Wang¹, Bicheng Kuang¹, Peijin Liu³, Wen Ao⁴

Affiliations

¹ National Key Laboratory of Solid Rocket Propulsion, Northwestern Polytechnical University, Xi'an 710072, China.
² Academy of Aerospace Solid Propulsion Technology, Xi'an 710025, China.
³ National Key Laboratory of Solid Rocket Propulsion, Northwestern Polytechnical University, Xi'an 710072, China; Ningbo Institute of Northwestern Polytechnical University, Ningbo 315000, China.
⁴ National Key Laboratory of Solid Rocket Propulsion, Northwestern Polytechnical University, Xi'an 710072, China. Electronic address: aw@nwpu.edu.cn.

PMID: 39418767
DOI: 10.1016/j.ultsonch.2024.107107

Abstract

The regulation of propellant combustion using ultrasonic waves is proposed. Under ultrasonic frequencies of 25-40 kHz, we systematically examined the combustion characteristics of Al particles, ammonium perchlorate (AP)/hydroxyl-terminated polybutadiene (HTPB) propellants, and Al-containing Al/AP/HTPB propellants. Ultrasonic treatment increased the ignition delay time of the Al particles by 48.3 %. However, it increased the burning rate of the AP/HTPB propellants by up to 26.1 % and decreased their ignition delay by 39.3 %. As the ultrasonic frequency increased, the burning rate of the solid Al/AP/HTPB propellants increased by 22.5 %, and the degree of Al agglomeration decreased, resulting in a 24 % decrease in the size of the condensed-phase combustion products. The action mechanism was analyzed in terms of the effects of ultrasonic waves on Al droplets and combustion flames. The introduction of ultrasonic waves split the Al droplets near the burning surface into smaller particles, which affected combustion efficiency. Bringing the diffusion flame closer to the burning surface affected the burning rate. These findings demonstrate that the combustion and agglomeration characteristics of solid propellants can be modified using ultrasonic techniques, providing a new method for controlling the thrust of solid rocket motors.

Keywords: Aluminum particles; Combustion; Solid composite propellants; Solid rocket motor; Ultrasound.