Structural Optimization And Performance Test Of Shear Probe Sensor

Ocean turbulence measurement is essential for understand ing the microstructure and m acroscopic m otion of the ocean. However, the efficiency way for the measurement is lim ited. The shear probe se nsor is spe cially desig ned f or the turbulence measurement. The m ovement of tu rbulence is that the large scale ed dy breaks and transform s into the sm all scale, and then to the sm aller scale. The larg e scale eddy obtains the energy from the m ain flow. So the kinetic dissipation rate becomes the important data of the turbulence dissipation.The shear p robe sensor is designed according to the property of turbu lence in order to obtain the kinetic dissipation ra te through the m easurement of the shear velocity. In the thesis, based on its operati ng principle, the structure param eters of shear probe sensor are optimized for the purpose of improving the voltage amplitude and enlarging the frequency range. Firstly, based on the theory of piezo-electricity, the relationships between the structure parameters, such as the length, width and thickness, of the piezoelectric ceram ic element (PCE) and the voltage and resonance frequency of the PCE are obtained. Thereby, the reasona ble structure parameters of the PCE are determined.Also,through ANSYS calculating, the influence of the sealed structure on the resonance frequency of the shear probe is achieved. The shape of the tip is confirmed by the fluid analysis. Finally, the performance of the sensor is estimated by fluid-structure coupling and wet m odal analysis. The relevant experim ents prove the properties of the shear probe reliability.The water experiments were conducted with the profiler which carried the shear sensors .The performance is analyzed by changing the depth and the state of the water. The result dem onstrated the optim al sens or m et the requirem ents to apply into operation and meanwhile it proved the feasibility of the optimization.