Effectiveness of a tiny tuned liquid damper on mitigating wind-induced responses of cylindrical solar tower based on elastic wind tunnel tests

A tiny TLD was specially designed and manufactured to investigate its effectiveness on mitigating the wind-induced responses of a 243-meter-high solar tower by using wind tunnel tests based on an elastic WA model. First, an elastic WA model of the solar tower was made, and its structural parameters, including natural frequency, the first three mode shapes and structural damping ratio, were identified. Second, six types of tiny TLDs with different inner diameters (9, 10, 11, 12, 13 and 14 mm) were designed and manufactured, and the natural frequency and sloshing damping ratio of water in these tiny TLDs were identified to compare them with the theoretical values. The results show the measured and theoretical natural frequencies agree well with each other, while the measured sloshing damping of water is much larger than the theoretical value. Then, a series of wind tunnel tests were carried out to obtain the wind-induced responses of the solar tower. The effectiveness of TLD on mitigating the wind-induced responses of the solar tower was systematically investigated based on a series of parametric studies. The results show the wind-induced responses in the cross-wind and along-wind directions, including the acceleration at the top, the shear and moment at the bottom, can all be significantly reduced by the tiny TLDs with optimized parameters. It seems that the efficiency of the TLDs at the vortex-induced vibration critical wind velocity is significantly higher than that at the design wind velocity. In addition, the parametric studies indicate that the effectiveness of the TLDs is considerably sensitive to the frequency ratio, the height of the TLDs and the mass ratio.