<<
[an error occurred while processing this directive] | [an error occurred while processing this directive] >>
Modification of Subfilter-scale Model in Large Eddy Simulation for Flow Field in Highway Tunnels
(1 Architecture and Civil Engineering Institute, TVTC, Taizhou 318000; 2 College of Urban Construction and Safety Engineering,Nanjing University of Technology, Nanjing 210009; 3 Green Building Research Center, Nanjing 210009)
Abstract The complexity of highway tunnel flow field has brought a lot of difficulties to numerical calculation, the problem of excessive dissipation of small-size eddy exists in both the dynamic eddy viscosity model and dynamic mixed model. The main reason is that there is strong shear stress for the turbulence near the wall of highway tunnels,causing large dissipation of small size eddy, but the simulated dissipation in the model is not sufficient to balance it.A study on turbulent energy cascade mechanism shows that the large-scale motion is not sensitive to the details of small-scale motion in the turbulent flow field, and as long as the SFS model provides appropriate kinetic energy dis-sipation rate, the roughly correct statistical law can be obtained from the simulation results of large scale motion.Based on the above ideas, an eddy viscosity coefficient model for highway tunnel flow field is proposed. The model can generate an appropriate kinetic energy dissipation rate so as to balance the energy dissipation of SFS motion. Its accuracy is verified and the effect is ideal through the comparison of the measured data of model and DNS calculation results.
Abstract：
The complexity of highway tunnel flow field has brought a lot of difficulties to numerical calculation, the problem of excessive dissipation of small-size eddy exists in both the dynamic eddy viscosity model and dynamic mixed model. The main reason is that there is strong shear stress for the turbulence near the wall of highway tunnels,causing large dissipation of small size eddy, but the simulated dissipation in the model is not sufficient to balance it.A study on turbulent energy cascade mechanism shows that the large-scale motion is not sensitive to the details of small-scale motion in the turbulent flow field, and as long as the SFS model provides appropriate kinetic energy dis-sipation rate, the roughly correct statistical law can be obtained from the simulation results of large scale motion.Based on the above ideas, an eddy viscosity coefficient model for highway tunnel flow field is proposed. The model can generate an appropriate kinetic energy dissipation rate so as to balance the energy dissipation of SFS motion. Its accuracy is verified and the effect is ideal through the comparison of the measured data of model and DNS calculation results.
.Modification of Subfilter-scale Model in Large Eddy Simulation for Flow Field in Highway Tunnels[J] MODERN TUNNELLING TECHNOLOGY, 2018,V55(6): 124-130
2018, Vol. 55 