Abstract:Tower-type truss artificial reefs have superior structural stability but are large and of low quality. Presently, few studies have investigated the water dynamics of complex structure reefs in China. Based on studies of the flow field effect around the tower-type truss artificial reef, hoping to provide reference to planning and layout. The reef hemline was 10400 mm long, 5000 mm high, 10400 mm wide, and the cement column was 2850 m minimum length. The diameter was 76.3 mm, the large disc diameter of the reef was 1200 mm, the thickness of the large disc was 59 mm, the small disc diameter of the reef was 680 mm, and the thickness of the small disc was 92 mm. Six real flow velocities (0.2, 0.4, 0.6, 0.8, 1.0, and 1.2 m/s) were designed to study the flow field around the reef. According to the similarity principle, the experiment velocities were 0.031, 0.063, 0.095, 0.126, 0.158, and 0.190 m/s. Using a water flume physical model test and particle image velocimetry (PIV) technology, the flow field effect around the tower-type truss artificial reef was evaluated under six different flow velocities. The anti-rolling and anti-slide coefficients were evaluated under different test conditions. The experimental results indicated that for the monomer reef by mode of 45° and 90° against the flow, the average and maximum upwelling velocity was increased with the flow velocity. The maximum upwelling velocity of the single reef 90° against the flow was 15.6%-21.0% the flow velocity, and 45° against the flow was 16.3%-23.5% of the flow velocity. Increases in flow velocity first increased and then decreased the upwelling scale and height, and when the coming flow speed was 0.095 m/s, the maximum upwelling scale and height were achieved. The slow flow area decreased with increasing flow velocity. Under the same flow velocity, the size of the slow flow area with 45° against the flow was greater than 90° against the flow. The length of the slow flow area to the reef height decreased with increasing flow velocity, and the trend decreased with increasing flow velocity. The length of the slow flow area with 45° against the flow was 13-24-fold longer than the height of the reef. The length of the slow flow area with 90° facing the flow was 11-22-fold longer than the height of the reef. The reef remained stable on the sea floor, where the water depth was 20 m and the current velocity was 1.2 m/s.