大气边界层风洞的风机动力系统优化设计

摘要

为满足风洞实验模拟真实野外大气边界层的要求,提出了双风机驱动的风机动力系统方案,并采用数值风洞技术对双风机的3种不同布置方案和单风机驱动条件下风洞内定常边界层流动特性及风机系统动力性能进行了对比分析.数值模拟结果表明:3种双风机动力系统方案均可满足风沙迁移全领域的风速要求;相比之下,双风机两端分布的设计方案在保证低惯性的前提下,使风洞内边界层流动最大风速和湍流度值最高可达54.28 m/s和13.46％,是单风机驱动情况下的176.60％和141.83％,更适于进行野外风沙迁移乃至沙尘暴过程的风洞模拟,是4种风洞动力系统设计方案中最优化的结果,可应用于现有沙风洞的升级改造.%A power system with dual fans for atmospherical boundary layer (ABL) wind-tunnel is proposed to simulate the actual ABL.Numerical wind-tunnel technology is used to compare the steady boundary flow fields in the wind tunnel among four schemes of the wind tunnel power system,that is,three different arrangement schemes of dual-fan power system a scheme of single power fan.Simulation results show that the dual-fan systems generate the wind velocity enough to cover whole condition of aeolian sand transport.Especially when the air in the wind-tunnel is driven by dual fans located at both ends of the wind-tunnel,the wind velocity and turbulence intensity of the boundary layer flow reach 54.28 m/s and 13.46％,respectively,and are 176.60％ and 141.83％ of those of single fan scheme.So it is most suitable for simulations of field aeolian sand transport or even sand storm processes in ABL wind-tunnel.The power system with dual fans located at both ends of the wind-tunnel is the optimal scheme among the four schemes of the wind tunnel power system.This research may provide a reference for the improvement of existing wind-tunnel involving sand motion.