Frequency response of a fixed-fixed pipe immersed in viscous fluids, conveying internal steady flow

摘要

Novel methods are desired to harvest and store power in harsh environments, like those found at the bottom of production wells, to power commercially available monitoring devices. These systems must not only be mechanically robust but also operationally resilient, capable of sufficient power output under the widely varying conditions expected over the service life of a well. Since energy harvesting systems are heavily dependent on natural frequency, this broad range of conditions and/or well configurations makes the design of a suitable energy harvester challenging. Although the American Petroleum Institute (API) has set standards on some of the system variables, other variables are less well defined and may be time dependent. A first step towards the design of an energy harvesting system, then, is to investigate the changes in the natural frequency of a well by varying those inputs possessing moderate to high uncertainty.