Design And Realization Of Wind Tunnel Measure And Control System Based On Virtual Instrument

Wind tunnel is the base of the aerodynamic and teaching，and it is used for aerodynamicsimulation test, getting all sorts of aerodynamic parameters. Wind tunnel X is a small lowspeed wind tunnel for teaching experiment of northwestern polytechnical university. Thewind tunnel uses measurement and control system which is based on virtual instrument, and itmakes up for the deficiency of the previous wind tunnel measurement and control system. Theformer measurement and control system mostly adopts the MS-DOS operating system, andthe programming language is FORTRAN language. Experimental program inwriting,modifying is inconvenient, and the measure precision and control accuracy of thesystem is not high. It is already can’t meet the requirements of modern computer technologyand aerospace technology.The article is studying on the composition principle and related technology of the windtunnel measurement and control system. After detailed analysis on the needs of users, thedesign idea of using virtual instrument technology, completed the measurement and controlsystem hardware and software design. The wind tunnel measurement and control systemconsists of two parts, which are data acquisition and processing and control. Its control systemcombines the console manual control and computer automatic control, and uses the PIDalgorithm to realize steady speed pressure control. Motor control adopts ac frequencyconversion speed regulation system. The measuring system is by computer throughPCI-1716S multi-function data acquisition card to complete the data acquisition andprocessing. Temperature measurement uses atmospheric temperature transmitter. Pressuremeasurement uses atmospheric pressure transmitter. Dynamic pressure measurement usesdifferential pressure transmitter. Force measurement using six-component balance. Themeasurement and control system software is based on modular design idea, usingLabWindows/CVI8.5to develop software.The wind tunnel measurement and control system which is designed in this article, afterdebugging, has been put into use. Many experiments show that the wind tunnel measurementand control system has reached the design requirements, high degree of automation, friendlyinterface, easy to use, high control precision and measurement precision, fully meet the requirements of laboratory teaching.