Design And Performance Study Of Small Return Flow Icing Wind Tunnel

In order to explore the icing and deicing problems of wind turbines and aircraft,it is very difficult and time-consuming to find the icing meteorological conditions that meet the requirements of cloud and fog parameters such as liquid water content and droplet diameter in the natural environment.The icing wind tunnel can simulate the required icing meteorological conditions through the refrigeration system and the spray system,so as to realize the tests that are difficult to complete in the real meteorological environment with lower cost and higher safety.In this thesis,a small recirculation icing wind tunnel is designed and constructed,including the spray system and various components of the wind tunnel.After the icing wind tunnel was built,the flow field verification of the icing wind tunnel was carried out,and the liquid water content in the icing wind tunnel,the measurement and calibration methods of the droplet diameter were studied.The calculation method of cylinder and airfoil icing is explored.Using FENSAP-ICE to simulate the twodimensional ice shape under different icing parameters,using the same icing parameters(temperature,LWC,MVD,incoming flow velocity)as the simulation calculation,the icing test was carried out through the icing wind tunnel,The ice profile was observed in the test section and its curve was recorded,and compared and analyzed with the results of the calculation and simulation.The speed of the test section is calibrated for the wind tunnel at room temperature,and the speed of the test section is 6m/s ? 30m/s.For the situation that the diameter of water droplets in the icing wind tunnel is single or the distribution is relatively concentrated,a method for calibrating the diameter of water droplets by combining numerical calculation and icing wind tunnel test is proposed.The rapid measurement of the droplet diameter is realized,and the experimental water droplet diameter is obtained.The diameter of water droplets in the spray system is 20-100 um.The ice blade method was used to measure and calibrate the LWC,and the overall distribution of the liquid water content in the test section was obtained.The experimental measurement found that the ice blade calibration method was within the allowable error range.The liquid water content is distributed in the range of 0.3 to 1.5kg/m3.In the icing performance study,cylindrical,0012 and 4415 airfoils were selected.Ice shapes of different sizes were obtained,and the ice growth process of the ice shapes was obtained through experiments.The results were compared with the results obtained by calculation and simulation under the same working conditions.The ice shape profiles of the two were in good agreement.It is proved that the icing performance of the icing wind tunnel is reliable.