Design And Test On Small Low-speed Wind Tunnel

For the problems of the large wind tunnel with costly and high start-up costs, a kind of small low-speed wind tunnel that could provide a stable source of wind quickly and accurately is designed according to the designing requirements of the wind tunnel, in order to measure, testing and calibration the equipment such as thermal wind sensor with low cost, set sand meter and the pitot. The wind tunnel is the one with closed circular low speed which the total scale length is 1.91m, the inlet diameter is 60mm, while the test section diameter is 100mm and the length is 260mm. Hexagonal cellular network with the thick of 0.06mm and 3 layer damping network are used to rectify the airflow, exploiting the increased large angle diffusion section to improve the shrinkage ratio in order to obtain a relatively stable uniform flow field. The methods of theoretical analysis, numerical simulation and experimental analysis were used to study the rectification performance of the wind tunnel. The results showed that the wind speed of the entrance was 0-38.6m/s, while the speed of test section was 0-21.6m/s, the accuracy of the wind speed could achieve 0.2m/s; The internal airflow of the experimental section has better uniformity and stability, the thickness of the boundary layer is about lmm, the static pressure gradient of direction airflow is small, and the flow field stable part account for more than 70% of its cross-sectional area, that could meet the designed requirements of the experiment.