Experimetal Study On The Passive Simulation Of Turbulence In The Boundary Layer

The simulation of boundary layer is the first precondition of wind tunnel test. Mostarticles in the past concern more about the velocity curve along the height scale and takethe turbulence at the building model height as the reference of turbulence field. In theyear2012, the updated ‘load code for the design of building structures’(GB50009-2012)changed the wind profile index under B category from0.15to0.16, upgraded the gradientheight under C and D category to450and550m, and also made specific calculation rulesabout the turbulence profile. In this ariticle, the passive simulation method has beenchanged accordingly: first, the influence of5individual passive devices have beendiscussed, and then combined to get the ideal boundary flow field as the code regulatedand the homogenous turbulence flow field as well. Finally, the effect of differenceturbulence profile has been discussed by comparing the wind load on TTU and CAARCbuilding model.The work of this ariticle can be listed as follows:1. Systematical discussion of the function of spires, hedge, roughness elements,carpet and the grid. Found the effects of them individually and figure out possible waysto combine their functions.2. Accomplished the layout patterns of A B C D landscapes category in the windtunnel fitting for different model scales from1:300to1:50. The main job is to make thewind velocity profile and the turbulence profile gets closer to the ideal curve bycalculation. In the following anysis, turbulence integral scale and power spectrum havebeen discussed. And all the results have been uploaded to the boundary layer simulationdatadbase of Harbin Intitute of technology.3. By changing the location of the gird, homogenous turbulence flow fields withdifferent turbulence intensity from6%to12%have been achieved.4. By comparing the TTU and CAARC results under different turbulence profileindividually, the necessity and effects of changing passive silmulation method have beendiscussed. Also, Results under the passive simulation method of this article agrees wellwith that of other insititutions and with the data of the original full scale model. Thus, theaccuracy of this experiment and the effects of difference turbulence profile have beenverified.