Setting up of Strouhal number at high Reynolds number region and experimental study of thermometer wells

摘要

When we design thermometer wells, the ratio of the vortex shedding frequency to the natural frequency of thermometer wells should not exceed 0.8 to avoid well failures caused by flow-induced vibration. But the Strouhal number used in thecalculation of vortex shedding frequency is not standardized at high Reynolds number region.So we decide the Strouhal number at high Reynolds number region, by means of behavior of an oscillating cylinder with lock-in condition and with surface roughness of thermometer wells.And lock-in for a single cylinder can be avoided by the other method by using reduced velocity and reduced damping parameter. We measure the natural frequency and the damping parameter of taper type thermometer wells with thermocouple to apply the method, and carry out the evaluation using sample thermometer well.