Scale Effect on Hydrodynamic Model Testing of the Submerged Floating Tunnel

Abstract

Submerged Floating Tunnel (SFT) represents an innovative solution for underwater infrastructure, designed specifically for cross-sea transportation in challenging deep-water regions. Due to the large-scale cross-section, the existing experimental studies have been performed in small scales of 1:50 to 1:150. This would inevitably lead to the distortion of viscous forces, due to the different Reynolds number between the full-scale and model scale SFTs. Hence, in this study, a two-dimensional viscous CFD model is set to simulate the scale effect on the hydrodynamic model testing of the SFT. The current loads acting on the SFT are compared for a series of scale ratios under various current velocities. It is found that both the drag and lift coefficients of the SFT present significant deviation for a wide range of scale ratio from 1:10 to 1:100, including an underestimated drag coefficient of maximum 58% for λ = 1:10 and an overestimated lift coefficient of 15.7 times higher than the prototype values. The dependence of the scale effect on the Reynolds number is demonstrated and highlighted. Thus, it is imperative to account for this disparity in both experimental investigations and computational simulations.

Keywords

Submerged floating tunnel / Scale effect / CFD modeling / Current load / Model testing

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