Tuned liquid dampers are one of the methods used to mitigate the dynamic response of a system to external excitation. The thesis includes a classification and description of tuned vibration dampers, with a focus on liquid ones. Furthermore, a demonstrator of a tuned liquid column damper (TLCD) with variable liquid damping is designed. An adequate mathematical model based on Lagrange's equations of the second kind is derived in detail. The resulting equations of motion are adapted for a numerical solution using the ode45 solver in Matlab. The designed demonstrator is then constructed, and its influence on the structural dynamic response is experimentally tested under free vibration conditions. The measurement results show a significant reduction in the dynamic response to an initial displacement when the damper is activated, confirming that the magnitude of liquid damping significantly influences the damper's effectiveness. The optimal value of the head loss coefficient was found to be 6,35. The mathematical model corresponds well with reality, while slight discrepancies occur primarily due to the simplified viscous modeling of the demonstrator's self-damping. The constructed device can be utilized in education to visually demonstrate the mitigation of undesirable vibrations.