Investigation of Head Loss Coefficient in a Novel Bidirectional Tuned Liquid Column Gas Damper: An Experimental Approach

This study investigates the experimental evaluation and analytical calibration of the head loss coefficient in a novel Bidirectional Tuned Liquid Column Gas Damper (BTLCGD), a passive fluid-based vibration mitigation device. The BTLCGD offers two-dimensional damping capability and can be tuned via internal gas pressure to match the fundamental frequency of the structure. Free and forced vibration tests were conducted using a physical model placed on a shaking table, where the damper was tested under various orifice blocking ratios and internal pressures. The results confirmed that the damper's natural frequency can be reliably predicted by an analytical expression, with a deviation of less than ۵% from the experimental measurements. It was further observed that the head loss coefficient is predominantly influenced by the orifice blockage ratio, while being mainly independent of the damper's orientation, gas pressure, and liquid mass. A modified empirical formula was also proposed to better estimate the total head loss by accounting for additional energy dissipation effects, such as elbow geometry and fluid viscosity. The findings provide valuable insights for the design and optimization of fluid-based dampers in civil and offshore engineering applications.

کلیدواژه ها:

Physical modeling ، Bidirectional tuned liquid column gas damper ، Head loss coefficient ، Harmonic excitation ، Shaking table