激光微烧蚀液态含能工质推进性能实验研究

Aimming at the mechanics problem of the interaction between laser and liquid energetic propellant, the liquid energetic propellant is adopted as the research object. The small scale plume optical diagnostic method is used to study the plume evolution process in laser ablated the liquid energetic propellant so as to obtain the temporal and spatial variation rules of plume jet volume and velocity and analyze the mechanism of laser energy deposition induced thrust generation. Based on the torsional micro-impulse measurement system and micro-mass measurement system, the variation rules of impulse coupling coefficient and specific impulse is studied so as to analyze the optimal operating point of the propulsion performance. The research results can reveal the effects of liquid viscosity and chemical energy release in the propulsion performance of laser micro ablation, and can obtain the control mechanism and law of laser parameters on the performance of liquid energetic propellant. The research can also promote the technology development of liquid energetic propullent in laser micro propulsion..The research results are a crucial base for the study on how to obtain the optimal propulsion performance when the laser interacting with the liquid energetic propellant. What is more, the resultes have great significances on enriching the theory of the interation between laser and liquid energetic propullent, and promoting the development of laser micro propulsion with liquid energetic propellant.

以液态含能工质为研究对象，针对激光与液态含能工质相互作用产生的力学问题，采用小尺度羽流光学诊断方法，研究羽流喷射演化过程，获得羽流喷射量和喷射速度的时空变化规律，分析激光能量沉积诱发羽流喷射推力产生机理；采用扭摆微冲量测量系统和微烧蚀质量测量系统，研究冲量耦合系数和比冲等推进性能参数变化规律，分析推进性能最优工况点的规律性变化。项目将揭示液态含能工质粘性、化学能释放对激光微烧蚀推进性能的影响，获得激光参数对液态含能工质推进性能的控制机理和规律，进一步促进液态含能工质在激光微推进技术中的应用。.研究成果将为激光与含能工质耦合如何产生最优推进性能这一科学问题奠定基础，对于丰富激光与液态含能工质相互作用理论，促进液态含能工质激光微推进技术也有重要意义。

项目以液态含能工质为研究对象，针对激光与液态含能工质相互作用产生的力学问题，采用小尺度羽流光学诊断方法和扭摆微冲量测量系统，分析激光与液态含能工质力学耦合机制及控制规律。.首先，实验研究了添加纳米碳粉含能工质GAP力学特性、羽流喷射特性及相应的控制规律。研究发现，添加纳米碳粉的含能工质GAP能够显著提升工质对激光能量的利用率，但冲量耦合系数和比冲不随添加浓度的增加而显著增加，添加纳米碳粉增加了GAP工质对激光能量的吸收，促进了化学能的释放，但受浓度的影响有限。羽流特性实验发现，未掺杂纳米碳粉GAP工质的气化程度较低，烧蚀产物以大质量块的形式喷出。掺杂高浓度纳米碳粉后的GAP工质对激光的吸收深度降低，表现出类似金属工质的面吸收特性。.其次，实验研究了添加红外染料含能工质GAP力学特性、羽流喷射特性及相应的控制规律。研究发现，添加红外染料的含能工质GAP对激光能量的吸收增强，因而所需激光功率密度阈值降低，红外染料掺杂浓度为5%时GAP工质的烧蚀效率最高，最优值接近200%。羽流特性实验发现，随着添加浓度升高，GAP工质对激光的吸收率提高，烧蚀深度降低。在烧蚀区形成的类似球形膨胀过程中，外层工质因未完全烧蚀因而在羽流中以液态的形式喷出。.最后，实验研究了圆锥形坑约束对激光烧蚀含能GAP推进性能的影响研究。分析喉部直径、扩张角、面积比三个约束因素对力学特性的影响。当喉部直径与激光烧蚀光斑在工质表面形成的初始喷射空间尺度相当时，冲量耦合系数和比冲等参数均表现较好；增大扩张角可提高力学性能，但存在最优值；随着面积比的增大，离子的喷射速度逐渐增大，但在最优值后对喷射羽流的加速作用逐渐减弱。此外发现离子喷射速度可以间接反映其力学特性。.本项目研究揭示了不同掺杂的含能工质化学能释放对激光微烧蚀推进性能的影响，得到了激光参数对液态含能工质推进性能的控制特性和规律，可为星载激光微推进技术应用奠定基础。