双层客车通风模拟与送风均匀性优化

Ventilation Simulation and Uniformity Optimization of Air Supply for Double-deck Passenger Cars

针对双层铁路客车客室送风均匀性问题,建立双层客车风道及客室通风数值计算模型,分析风道的送风均匀性和车内风速大小,按照ASHRAE23的相关舒适性评价指标对客室风速场进行评估,并依据仿真结果进行优化。研究表明,等截面风道不能满足均匀送风要求,其头部出风量小、尾部出风量大,内部风口的出风有很大的纵向速度,导致风量沿风道下游端部聚集;风道直角拐角处压力损失大,采用圆角过渡能有效减小局部流动阻力,减小幅度达40%;风道出风口处静压腔空间较小,不能有效减小内部风口处射流冲击,需要用横向整流措施来减小气流的纵向速度;增加横向整流板、引流板、阻力板、三角导流板等措施能有效调节风道沿纵向的出风均匀性;综合风道优化措施能在不改变原有风道安装空间和外形的情况下,保证车内送风的均匀性且满足标准要求。

Aiming at the issue of the uniformity of air supply in the passenger compartment of a double-deck passenger car,a numerical calculation model for double-deck passenger car air duct and passenger room ventilation is established,and the airflow uniformity of the air duct and the wind speed inside the vehicle are analyzed.According to the relevant comfort evaluation index in ASHRAE 23,the velocity field in the passenger compartment is evaluated and optimized based on the numerical results.The result shows that the air duct with a constant cross-section cannot satisfy the uniform requirement for air supply,the airflow volume in the beginning of the air duct is small,whereas the air volume in the end is large,and the outflow of the inner outlet has a large longitudinal velocity,which causes the airflow gathering along the downstream of the air duct.The pressure loss at the right corner is large,and the rounded transition can effectively reduce the local flow resistance with an amplitude of 40%.The static pressure chamber at the air outlet is relative small,which can not effectively reduce the jet impact at the internal tuyere.Lateral rectification measures to reduce the longitudinal velocity of the airflow.Meanwhile,measures such as increasing the lateral rectifying plate,the deflector,the resistance plate,and the triangular baffle can effectively adjust the uniformity of the airflow along the longitudinal direction of the air duct.In the case of keeping the original air duct installation space and shape,the combined optimization measures ensures the uniformity of the air supply to satisfy the standard requirements.