| Wing icing will change its aerodynamic shape,resulting in reduced lift force,increased air resistance and reduced stalled angles of attack,which will directly affect the aerodynamic characteristics and maneuverability of the aircraft and lead to flight safety accidents.The Icing Wind Tunnel is a ground test facility simulating high altitude icing environment,which provides an icing test platform for aircraft icing performance analysis.However,the existing small Icing Wind Tunnel has the problems of complex structure,high energy consumption and high cost,so the simplified research of small Icing Wind Tunnel is of great significance.An L-type Icing Wind Tunnel experimental system using natural low temperature was designed and realized in this thesis,which in order to facilitate the study of the icing process of low-speed wing.The conventional closed icing wind tunnel with refrigeration system is innovatively changed to an open structure.By adding a direct connection structure between the power fan and the icing tunnel,all components are combined into a series structure,so as to realize engineering innovations such as simplification of engineering manufacturing,low cost and convenience of replacing test pieces in the experimental process,which has strong engineering application value.Meanwhile,it can provide a wing icing experimental platform for scientific research institutions and universities for wing icing performance analysis and anti-icing/deicing research.The icing parameter similarity equations between simulated icing and actual icing was established by using the icing similarity criterion,and the simulation ability of environmental parameters of icing wind tunnel was estimated to reach 10 to 50?m of average droplet diameter and 22.0g/m~3 of the maximum water content.The structure and size of Icing Wind Tunnel were designed by using the theory of tunnel pressure loss calculation,Vickers formula and friction loss.The wing icing was simulated by FLUENT and FENSAP-ICE,and the standard wing icing thickness range of 4.68 to 24.16mm was formulated to verify the design size and icing performance of the Icing Wind Tunnel.The Icing Wind Tunnel was fabricated by selecting and machining aluminum alloy and acrylic plate materials.The power source fan was determined by calculating the total pressure loss along the Icing Wind Tunnel,and the turbulence value of the test section was less than 0.8%.The complete spray system was consisted of the water tank,water pump,water temperature controller,regulator and sprinkler and other equipment to complete wing icing experimental platform of the Icing Wind Tunnel.The experiment of Icing Wind Tunnel was carried out using the natural low temperature environment of Jilin City in Northeast China.Firstly,the performance of Icing Wind Tunnel was tested,and the maximum wind speed was 18.5m/s;A single nozzle and double nozzles spray method was used to carry out the ice icing contrast experiment.The ice thickness of the wing front was analyzed,and the flow field quality of the icing wind tunnel test section was great.Secondly,the measurement experiments of average droplet diameter and water content were carried out,and the average droplet diameter and water content ranges of this icing wind tunnel were 26.3 to 32.5?m and 0.8 to 1.9g/m~3 respectively.The average dimensionless icing areas of the two wings were 0.36 and 0.44 respectively,which were higher than the design theoretical value of 0.2,so the icing effect was great.Finally,it was obtained that the simulation and actual icing have strong similarity in the variation trend of wing icing profile and thickness through the comparative experiment,and the actual average icing thickness of wing front was8.81mm,which was in the range of standard wing icing thickness of 4.68 to 24.16mm,which verified the scientific of design of Icing Wind Tunnel. |
PDF Full Text Request