Ablation of carbon-doped liquid propellant in laser plasma propulsion
- PDF / 632,217 Bytes
- 4 Pages / 595.276 x 790.866 pts Page_size
- 0 Downloads / 204 Views
Ablation of carbon-doped liquid propellant in laser plasma propulsion Z. Y. Zheng1 • T. Liang1 • S. Q. Zhang1 • L. Gao1 • H. Gao1 • Z. L. Zhang1
Received: 8 September 2015 / Accepted: 10 November 2015 Ó Springer-Verlag Berlin Heidelberg 2016
Abstract Carbon-doped liquid glycerol ablated by nanosecond pulse laser is investigated in laser plasma propulsion. It is found that the propulsion is much more correlated with the carbon content. The doped carbon can change the laser intensity and laser focal position so as to reduce the splashing quantity of the glycerol. Less consumption of the liquid volume results in a high specific impulse.
1 Introduction Remarkable progress has been made in recent years in laser plasma propulsion due to its high payload efficiency and potential low cost. In terms of target materials, liquid propellants are considered as an optimum material because it significantly enhances the thrust as compared to solid materials [1–6]. Many experiments have been performed to investigate the interaction between laser pulses with liquids and liquid-containing materials. In addition to water, a few other liquid propellants such as diethyl ether, ethylene glycol and castor oil have been tested [7]. For example, a high coupling coefficient of 350 dyne/W was achieved with water film as the propellant [8]. Through a confinement target configuration, the coupling coefficient of a water propellant is enhanced more than an order of magnitude as compared to direct ablation [9]. However, for all liquid propellants, serious splashing behavior is observed in ablation. A very low specific impulse is generated accordingly. This is essentially due to the splashing of the liquid, which drives out the laser & Z. Y. Zheng [email protected] 1
School of Science, China University of Geosciences, Beijing 100083, China
energy into droplet formation instead of high velocity plasma acceleration. In order to enhance the specific impulse, small containers or droplets, as well as doped liquids, are used to reduce the splashing. In addition, the viscosity of liquid propellants has been tested to correlate it with the propulsion efficiency [10, 11]. An almost linear relationship between the coupling coefficient and specific impulse with the viscosity of the water serving as the propellant was found [10]. Shadowgraph images reveal that the splashing behavior can be controlled by the viscosity [11]. Furthermore, some groups adopted carbon as the doping material to reduce the splashing. In experiment, carbon-ink-doped water was used as the liquid propellant and 19 s of specific impulse was achieved [3]. Considering both the doping method and liquid viscosity, the carbon-doped glycerol has been proposed recently to reduce the splashing and to enhance the specific impulse [1, 12]. In these papers, only the shadowgraph images revealing the time evolution of the splashing are described, but the specific values of the coupling coefficient and the specific impulse are not given. Also, the effect of the carbon on the propulsion is not
Data Loading...
