Research On The Coefficients Of Tri-component For Sections Of Bridge Under Different Reynolds Number

The Reynolds number effect of the aerostatic coefficients of Tri-component was usually neglected in the bridge wind resistance designs. But with the bridge gradually develop towards long span and light weight aspects, it will more obvious that the effects of Reynolds number makes on the aerostatic coefficients of Tri-component, the designs of bridge wind-resistance will be distortion or even dangerous when designers neglect the gradually obvious Reynolds number effects. Therefore, it's very necessary to conduct an investigation in the Reynolds number effects of the aerostatic coefficients of Tri-component. Until now, the wind tunnel test is the main approach to study the Reynolds number effects of the aerostatic coefficients of Tri-component, which is well developed. But it costs considerable labors,funds and times. With the speedy development of the computer technology and computational fluid dynamics, the method of computational fluid dynamics is the new means of study the aerostatic coefficients of Tri-component, which is known as numerical wind tunnel. It can do computation with full scale and overcome the shortage of the wind tunnel test.The study object of the paper is the aerostatic coefficients of Tri-component. Through analyzing the Reynolds number effects of the aerostatic coefficients of Tri-component by the method of computational fluid dynamics, it was concluded that is the change law of the aerostatic coefficients of Tri-component along with Reynolds number change.(1) Based on Jana Bridge and Sutton Bridge, three different turbulent models, such as k-εmodal, RNG k-εmodal and SST modal, have been used in this paper to recognize the aerostatic coefficients of Tri-component by the method of computational fluid dynamics. Comparing the results of numerical simulation with those of wind tunnel test, it was proved that the k-εmodal is appropriate modal of recognizing the aerostatic coefficients of Tri-component, and the effectiveness of recognizing by computational fluid dynamics method.(2) Through analyzing the Reynolds number effects of the aerostatic coefficients of Tri-component of circular and rectangular by the method of computational fluid dynamics when the angle of attack is zero, it is find that the drag coefficient and lift coefficient of circular increase along with the increase of Reynolds number. The drag coefficient and lifting moment coefficient of rectangular increase along with the increase of Reynolds number, the lift coefficient is just the opposite. Following this rule, the others are also different. So the Reynolds number effects of different shapes shouldn't neglect in the aerodynamic type selection.(3) Through analyzing the Reynolds number effects of the aerostatic coefficients of Tri-component of bluff body and streamline bridge deck by the method of computational fluid dynamics when the angle of attack is zero, it is find that the drag coefficient and lifting moment coefficient of bluff body bridge deck increase along with the increase of Reynolds number, the lift coefficient is just the opposite. The drag coefficient, lift coefficient and lifting moment coefficient of streamline bridge deck decline along with the increase of Reynolds number. So the Reynolds number effects of different type bridge deck shouldn't neglect in the aerodynamic type selection.(4) Through analyzing the Reynolds number effects of the aerostatic coefficients of Tri-component of three streamline bridge decks by the method of computational fluid dynamics when the angle of attack is zero, it is finding that the feature of the streamline bridge deck is free from the width-depth ratio.The research works have a certain reference value for the aerodynamic type selection in this paper.