Construction Of Direct-current Type Low-speed Wind Tunnel Test Platform And Its Entire Flow Field Aero Dynamic Properties Research

Wind Tunnel is a pipeline experimental equipment used in aerodynamic research.It is the most common aerodynamic tests method and most effective tool to study theeffects of air moving past an aircraft or solid objects. The quality of the wind tunneltest section flow field will directly affect the accuracy and reliability of the results ofwind tunnel experiments, so it is very necessary to measure and evaluate the qualityof the wind tunnel flow field before an experimental aerodynamics research.Including wind tunnel test section, stable segment contraction section, diffuser,fan section and other parts of the body as well as cellular hole, a damping network,fairings and other internal components. The size of the DC low speed wind tunneltest section is500mm×300mm. In this paper, we need to design the structure andusing the three-dimensional numerical simulation of flow field simulation to analysisthe whole structure, starting research for the focus on a greater impact on the flowcharacteristics of the wind tunnel contraction section and fan system. Aerodynamiccharacteristics of DC-type low speed wind tunnel, the main structure of the model isto simulate the different parameters calculated, based on the analysis and comparisonof the results, and the choose the best structural performance.In the structural design of components: contraction curve in dual cubic curveand Vickers curves are the two ways to obtain two sets of segments contractedconfiguration parameters, and use three-dimensional graphics software Solidworkswere established contraction segment model; in the design of fan system, rotatingfan blades were selected Clark Y airfoil and the standard NACA0020airfoil; in thedesign of fairing, according to its aerodynamic shape curve formula, using Matlabprogramming method to obtain the hood and tail fairing cover curve; the structure ofseveral different number of blade designs were5,79, the installation angles of fanwere35°,40°,45°,using the software Solidworks to complete the structural modeling.In the numerical simulation part: using the mesh software Gambit and Fluenthydrodynamic analysis software, and various parts of the wind tunnel experimentplatform for the entire flow field characteristics analyzed to obtain the turbulent flowcharacteristics, such as strength, speed, pressure and flow field trace diagrams parameters. Based on the different structural models for numerical simulation,analysis and comparison of the calculated results, and ultimately determined: theflow characteristics of double three contraction is better than Vickers contractionsection; fan blades5, the installation angle of the fan system flow field of35°characteristics is the best. And verify the DC-type low speed wind tunnel testplatform full flow field characteristics, the test section turbulence intensity is2%,and the speed of the wind is22m/s, can meet the requirements about test sectionturbulence intensity and wind speed to design a flow field of quality to meet therequirements DC-type low speed wind tunnel experiment platform.This paper aims to develope an economical and practical small low speed windtunnel experimental device that can meet the basic needs of its wind engineeringresearch work, and also can be used for general teaching experiments andaerodynamic simulations. The research of this kind of wind tunnel for small-scalepractical wind tunnel are of practical significance for popularization and application.