Research On Sound Field Intensity Control For Underwater Seepage Bubble Flow Measurement Process

Sea cold spring is the main approach of the undersea gas leakage. Underwater leakage of cold spring is a widely distributed natural phenomenon in the marine environment, preliminary estimates released into the ocean every year by leakage of sea cold spring water and the amount of methane in the atmosphere is more than1012gram. For science, ecology, climate and the need of social and economic sustainable development, measurement of every year leakage released into the ocean water and the gases of the atmosphere measuring tool has important and far-reaching significance. At present, many international scholars have studied undersea gas seepage flow observation technology through experiment, but those methods which can realize online measurement still can not meet the measurement requirement of different submarine circumstances in numerous flow observation technologies. Our group has carried out preliminary research from the perspective of transmission acoustic waveform-amplitude parameter on measuring the undersea gas leakage bubble flow, preliminary measurement result shows that this method can measure the bubble flow effectively. Based on current result, our group has developed a new type of submarine gas leakage bubble flow sound waves in situ measurement system. In order to reach the requirements of automatic measurement on the submarine bubble flow, the measurement system needs to resist disturbance on the sound field intensity caused by the bubble volume fraction. Due to the underwater bubble flow statement is uncertain, the current sound wave measuring instrument is difficult to achieve these requirements. Therefore, how to adjust the sound intensity automatically and make sound field strength smooth under bubble volume fraction disturbance has become the crucial technology of a new in situ measurement system.With the aim to solve the above critical problems, based on the theory of sound propagation in bubble-water two phase medium, sound wave measuring bubble system acoustic intensity control model is established, the corresponding PID controller is designed and MATLAB SIMULINK simulation model is established at the same time. MATLAB xPC semi-physical simulation platform is setup based on fuzzy control algorithm meanwhile and experiment verification is also carried out. Simulation results show that the fuzzy controller designed by author has reached the expected precision. It can provide technical support for the undersea gas leakage bubble flow precise measurement.