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 interference can be effectively suppressed and the probability of target detection increases. The results of this study provide a basis for studying ultrasonic microtopography detection in the deep sea mining reverberation environment.