Numerical investigation on aerodynamic performance of a streamlined box deck accounting for Stokes wave boundary effects

Abstract

The aerodynamic performance of a streamlined box deck as a result of interactions with the Stokes wave boundary is not well investigated when the bridge deck is close to the water surface. Therefore, it is necessary to conduct the aerodynamic performance investigation of a streamlined box deck accounting for Stokes wave boundary effects. In present study, the common aerodynamic characteristics about aerostatic force coefficients, basic flow features and mean and fluctuating pressure coefficient distributions around the deck are investigated by the numerical simulations. First, the wind tunnel experiments which can simulate the aerostatic force coefficients of a streamlined box deck under the influence of a solitary wave boundary model is introduced. Then, a 2D numerical model for solitary wave boundary is built and validated based on the wind tunnel experiments. After that, the Stokes 2nd order wave boundary and the layering mesh method are introduced into the validated numerical model to build a new numerical model for moving Stokes wave boundary and a series of parametric analysis including wave boundary moving speed (c), angle of wind incidence (α), Stokes wave height (H2) and bridge clearance (a) are carried out. The common aerodynamic characteristics accounting for the moving Stokes wave boundary are quite different from those of no-wave case. Due to the streamlined characteristic, there is no apparent vortex shedding observed, even at ±8° angles of wind incidence, but with apparent flow separation and shear layers around the deck. The bridge clearance (a) has the more significant effect on the force coefficients than wave height (H2). The results obtained may provide a preliminary grasp of the general aerodynamic performance of a streamlined box deck accounting for Stokes wave boundary effects and may be significant to the early design and construction stage when the elevation of the deck is not so high.