模拟深海采矿混响环境实验装置研究

针对真实深海采矿环境下实时微地形超声探测声信号获取难的问题,设计并建立了一套能模拟真实深海采矿混响环境的超声探测实验系统.在对螺旋采掘头结构简化的基础上,利用Fluent模拟了螺旋采掘头与多组叶轮模型对水下流场的影响,对二者所得的水下流场进行比较后,确定所选叶轮模型能较好地反映真实采矿环境.随后针对叶轮模型,实验测量了泥沙垂向浓度分布,验证了设计模型的正确性.最后进行超声探测实验,结果表明,悬浮泥沙不仅对声波产生黏滞和吸收,而且会产生严重的混响干扰,通过该超声探测系统的时间增益补偿,可有效抑制混响干扰,增加目标检测概率.本项研究为深海采矿混响环境下的超声微地形探测提供了研究基础.

Experimental device for simulating reverberation environment in deep sea mining

To solve the difficult problem of ultrasonic signal acquisition with respect to real-time tiny terrain detection in the deep-sea mining environment, an experimental ultrasonic detection system was designed and built that can simulate the real deep-sea mining reverberation environment. Using a simplified structure for the spiral mining head as a basis, Fluent software was used to simulate the impact of a spiral mining head and a multiple-impeller on the underwater flow field. A comparison of the results shows that the impeller model can realistically reflect the mining environment. Then, based on the impeller model, the vertical distribution of the sediment volume fractions is experimentally determined and the correctness of the design model is verified. Finally, an ultrasonic detection experiment is conducted and the results show that suspended sediment can generate viscosity and absorb sound waves, thereby causing serious reverberation interference. By implementing time-gain compensation in the ultrasonic detection system, the reverberation inter-ference can be effectively suppressed and the probability of target detection increases. The results of this study provide a basis for stud-ying ultrasonic microtopography detection in the deep sea mining reverberation environment.