Free-Stream Turbulence Measurement Using Hot-Wire Anemometer: An Undergraduate Laboratory Experience

An undergraduate laboratory experiment is designed to explore the application of hot-wire anemometry for measuring the free-stream turbulence in a low-speed wind tunnel. The experiment involves calibrating the hot-wire anemometer using a pitot tube, followed by a physics based polynomial curve fit to convert the voltage readings into flow velocity. The data is analyzed to compute the mean velocity and the free-stream turbulence intensity including their respective uncertainty analyses. The lab further explores the theoretical aspects of turbulence, operational principles of constant temperature and constant current hot-wire anemometer, experimental methodologies and the relevant theories to analyze and interpret the data. The primary learning objectives include introducing the principles of hot-wire anemometry to undergraduate students and measuring freestream turbulence intensity. This also allows students to expose themselves to calibration and data analysis methodologies. The discussions in the current paper can serve as a laboratory manual for the implementation of the experiment in a university setting. The student evaluation schemes and expected outcomes implemented at the UT Arlington are also discussed.