高温射流冲击下耐火混凝土烧蚀试验研究

Experimental study on ablation of refractory concrete under high temperature jet impact

为探究火箭高温尾焰射流冲击作用下混凝土的烧蚀行为,现以高铝质耐火混凝土试块为研究对象,通过浇筑定型烘干养护等手段制备试验成品,随后基于自主研发的氧煤油燃气发动机烧蚀系统调整出高温高速的试验工况,并采用编写程序的方式控制伺服电机以完成发动机及试样的移动,达到对烧蚀距离、角度及时间的调节,最终记录试验现象结合烧蚀结束后混凝土受火面宏观形貌与质量、线烧蚀率分析耐火混凝土热损伤进程。结果表明:高温高速射流冲击混凝土试块,受热面中心迅速升温呈炽红色,其面积随时间逐渐向周围扩张,且模态由固相转为熔融流态,烧蚀过程中持续飞溅出高温颗粒体。30 s试验结束后,测算耐火混凝土试块质量烧蚀率达0.302 g/s,线烧蚀率为0.177 mm/s。

In order to explore the ablation behavior of concrete under the impact of rocket high-temperature tail flame jet,the high-alumina refractory concrete test block is taken as the research object,and the finished product is prepared by means of casting,shaping,drying and curing.Subsequently,based on the independently developed oxy-kerosene gas engine ablation system,the high-temperature and high-speed test condition is adjusted,and the servo motor is controlled by means of programming to complete the movement of the engine and the test sample,so as to achieve the adjustment of the ablation distance,angle and time.Finally,the test phenomenon is recorded,and the thermal damage process of the refractory concrete is analyzed in combination with the macro-morphology and quality of the concrete receiving surface after ablation,and the linear ablation rate.The results show that when high temperature and high speed jet impact concrete test block,the center of the heating surface rapidly heats up and becomes incandescent red,and its area gradually expands to the surrounding with time,and the mode changes from solid phase to molten state,and high temperature particles continuously splash out during the ablation process.After 30 s test,it is estimated that the mass ablation rate of refractory concrete block is 0.302 g/s and the linear ablation rate is 0.177 mm/s.