Analysis For Temperature Field And Thermal Stress Of Composite Skin Of Wings During Electrothermal Anti-icing Process

The structure of the electrothermal anti-icing generally includes the composite material layer.It easily lead to uneven temperature distribution,resulting in larger thermal stress in layers and between layers when the anti-icing system works with the anisotropic heat transfer characteristics of the anti-icing structure.Therefore,it is necessary to calculate the transient temperature field and thermal stress field of the airfoil electrically heated anti-icing structure.The Euler's method was used to calculate the droplet impingement property on the external surface of the wing.The boundary layer integral method was used to calculate the convective heat transfer coefficient on the external surface of the wing.The results were contrasted with the literature results.In addition,the heat flow across the external surface of the wing was analyzed and calculated as the boundary condition of the thermal analysis.A three-dimensional anisotropic heat transfer model with internal heat source was established according to the wing skin electric heating structure.The control equation was discretized by the control volume integral method.A calculation program to calculate the transient temperature field of the structure was developed with MATLAB.Then,the structure temperature field of composite materials with different lay-up directions was calculated.The analysis shows that the external surface temperature of the wing is between 10?and 110?,which meets the anti-ice standard.In addition,the temperature curve has a good agreement with the results in the literature.When the fiber is oriented in the‘s'direction(?=90~o),the heat is diffused well in the chord direction,and the temperature profile along the chord is smoother.Also,the high temperature region is smaller and the highest temperature is lower.Based on ANSYS,the three-dimensional model of the skin layer under the wing-body coordinate system was established.The calculated transient temperature field of the anti-icing structure was loaded into the calculation model as the temperature load.The distribution of thermal stress and deformation was obtained by the transient thermal stress analysis.The results show that when the orientation of the fiber is‘s'(?=90~o),the deformation of the structure is smaller and the thermal stress of the inner wall is smaller.Comprehensive comparison of temperature and thermal stress analysis results:the composites with‘s'fiber direction have more advantages in preventing high temperature and large thermal stress in the anti-icing structure.