【作者】 吴丽萍；

【导师】 白志鹏；

【作者基本信息】 南开大学 ， 环境科学， 2012， 博士

【摘要】 裸土风蚀型开放源是我国城市环境空气颗粒污染物的主要排放源类，只有有效抑制颗粒物排放源，才能从根本上改善城市区域的空气质量。可移动式风蚀风洞是土壤风蚀起尘、迁移、传输等定量研究的重要和首选工具，它的应用能为风蚀预报模型参数本土化、土壤风蚀尘预测系统构建、裸土风蚀开放源防控管理技术措施制定等提供有效、可靠、可行的研究工具和技术手段。论文根据风蚀理论、风洞设计原理、风洞模拟大气边界层的相似理论，提出了可移动式风蚀风洞设计的空气动力学准则和设计条件。设计了NK-1可移动式风蚀风洞的气动轮廓，主要由进气段、动力段、过渡段、转角段、稳定段、收缩段、实验段和尾部扩散段组成，总高2.456m，全长15.9m。收缩段收缩比为2.0，风洞能量比为0.414。风洞设计风速为0.3~20m/s且连续可调，风洞各段之间易于连接和分离，便于野外测试时的移动和运输。NK-1可移动式风蚀风洞的独特设计在于，其一，利用转角设计形成具有向上20°仰角的气动结构，避免了动力段向上偏置产生的非对称性，风洞各段的对称结构设计有效降低了流动能耗，风洞结构更趋紧凑；其二，动力段为自主设计制造，包括风扇系统和导流片、整流罩的气动结构。通过选择高升阻比的翼型风扇，根据需要确定设计工况点，合理选择桨叶和导流片设计参数，如桨毂比、实度、升力系数和圆弧角等，以及整流罩流线型旋成体的设计与计算，验证了风扇系统效率，符合设计要求；其三，利用Fluent软件，引入多孔介质模型方法模拟实际地表大气边界层风速剖面，获得了棒栅+粗糙元组合的优化分布，室内外风洞试验表明，采用该人工大气边界层调节装置，可获得与实际地表相似的对数律平均风速剖面。利用风蚀风洞的数据采集与控制系统，完成了可移动式风蚀风洞实验段流场的空气动力学特征参数湍流度、气流稳定性、气流速度均匀性、轴向静压梯度、风洞能量比各项指标的测试，该风蚀风洞实验段流场性能满足设计要求。本研究为风蚀研究提供了有效的研究工具，为可移动式风蚀风洞的应用奠定了理论基础。更多还原

【Abstract】 The open sources were important for ambient PM, compared with other sources.A certain amounts of ambient are PM are derived from soil via wind erosion dustproduction procedure, especially in northern China. This is an effective way forimprove Urban air quality to control the particulate emission sources. Movable winderosion tunnel is a important and preferred tool to quantitative study on dust emission,migration and transmission caused by soil erosion procedure, with which effective,reliable, and feasible research tool and techniques can be provided for parameterslocalization of wind erosion predictive equations, construction of the wind erosionprediction system, the technological measures to prevent and control soil wind opensource, and so on.Based on the wind erosion theory, principle of wind tunnel design,atmospheric boundary layer similarity theory, some aerodynamic criteria anddesign conditions has been proposed for designing NK-1movable wind erosiontunnel, which was2.456meters high and15.9meters long composed of inlet section,power section, transition section, turning section, stability section, contraction section,working section and diffusing section. The wind erosion tunnel possessedcontraction ratio of2.0and energy ratio of0.414. The wind speed can be adjustedsmoothly by a frequency activator within the range of03～20m/s.The assembly anddisassembly of the tunnel components are easy to perform. It realized the functions ofmoving and transporting while using in the fields.The unique design of the NK-1movable wind erosion tunnel were: firstly，thewind erosion tunnel is a symmetry aerodynamic structure with an elevation of20°degrees, which can reach better energy efficiencies and structure compactness.Secondly, the power section is independently designed and manufactured includingthe design of a fan system, deflector and fairing. The efficiency of the fan system hasbeen verified by choosing a high lift drag ratio fan aerofoil, and determiningoperation point according to the needs of running, and choosing of parameters forrotor and fairing such as boss ratio, solidity, lift coefficient and camber angle etc. Thirdly, Fluent, a kind of CFD(Computational Fluid Dynamics) software, was used tosimulate the mean velocity profiles of atmospheric boundary layer by introducing theporous media model in NK-1movable wind erosion tunnel in order to get th optimaldistribution of stick grid-roughness elements, and the results was validatedsatisfactorily by the wind erosion tunnel experiments. The velocity profiles ofatmospheric boundary layer approach the logarithmic law similar to the groundsurface based the combination of stick grids and roughness elements.Appling the data acquisition and wind speed controlling system, some testswere finished refer to the main characteristic parameters testing of field aerodynamicsflows in the portable wind-tunnel such as turbulence intensity and distribution,airflow stability, air current horizontal homogeneity, pressure gradient on thedirection of axis, wind-tunnel energy ratio. The results show that the flow fieldperformance conforms to the design requirements in wind erosion tunnel. The studyprovides a effective tool for wind erosion studies both in fields and in laboratory. Onthe other hand, the study laid the theoretical foundations for applying the movablewind erosion tunnel.更多还原