도로터널 임계속도 산정에 난류모델 및 대류항 처리기법이 미치는 영향

초록

This study conducted comparative analysis to estimate critical velocity in tunnel fire under variation of turbulence model and convection schemes using three-dimensional computational fluid dynamics (CFD). In the target tunnel, by one-dimensional way, the calculated critical velocity in the tunnel, 2.22 m/s was estimated, if appling hydraulic diameter, instead of the tunnel height. From our results, the numerical analysis of three turbulence models reaffirmed that standard k-ε model has greater turbulence kinetic energy and turbulence kinetic energy dissipation compared to realizable k-ε and SST k-ω model. In the numerical results of convection schemes, 2nd upwind scheme was the larger backlayering than 1st upwind scheme and the larger gradient of temperature and CO concentration distribution. Therefore, it is necessary to decide appropriate grid number, turbulent model, convection schemes and the location and size of the fire source through comparison with actual experiment results and three-dimensional analysis.

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