Study On Ventilation Demand And Design Of Light Environment Of Awning Between Highway Adjacent Tunnel Portals

The "white hole" and "black hole" effects of the highway adjacent tunnel groups during the daytime has greatly aggravated the driver’s psychological and psychological burdens,and the high risk of accidents has long troubled the public’s safe travel.The successive tunnel awning can effectively alleviate the driver’s visual mutation.But the research on the parameter setting and ventilation type of the dimming material are rare,most of them were designed by experience in engineering practice.Based on the environment illumination,the adjacent tunnel spacing and the length of adjacent tunnel,carrying out study on ventilation demand and design of light environment of highway successive tunnel awning,and proposing a light environment design method for successive tunnel awning to meet the ventilation demand,which is of great significance for improving operation safety of the highway adjacent tunnel groups.First of all,the length,structure type,types of shading material,light transmission parameters and vent setting status of some awnings between highway adjacent tunnel portals in China are investigated,and its advantages and disadvantages are analyzed.Taking the adjacent tunnels of jinhong highway in yunnan province as the object,the direct shading feeling with the change of viewpoint illumination of a driver driving through successive tunnels are collected by driving experiments and the range of driver’s viewpoint illumination corresponding to the “black sensation” rating of the adjacent tunnel portals are obtained quantitatively.Choosing the change value of the driver’s viewpoint illumination without generating the "white hole" and "black hole" effects as the basic parameter of design of light environment of successive tunnel awnings.Based on the Ecotect Analysis light environment simulation technology,the single light transmission parameter and "three-segments" combination transmission parameters were studied,and the range of values of the dimming parameters for the design of the awning light environment under different environmental illumination levels and tunnel spacing was determined.Then,with preferred type A successive tunnel awning as the object,using ANSYS ICEM CFD three-dimensional modeling technology to construct the physical calculation model of adiacent tunnel and awning ventilation opening model.Three-dimensional numerical simulation analysis was carried out on the successive tunnel awnings with multiple ventilation opening schemes in Ansys Fluent environment,the influence data of "secondary pollution" in adjacent tunnels from upstream to downstream was obtained quantitatively,and the recommended range of the ventilation opening height selection of successive tunnel awning under different tunnel spacing was proposed.Finally,based on the Yunnan Province Geqiao highway,the design of light environment and ventilation of successive tunnel awning of Renhe-Zhangjialiangzi was completed.A way is explored by using the technology of light environment and fluid simulation combined to realize the selection of light transmission parameters and ventilation and smoke exhaust demands for successive tunnel awning that meet the driver’s visual adaptability,the design theories and methods of successive tunnel awning were proposed,which are of great significance for improving the traffic safety level of the adjacent tunnel groups.