IMPINJING JET ON A CONCAVE SURFACE FOR AIRCRAFT ANTI-ICING

Ice formation on airplane wing profile is a very dangerous condition because of the change in the profile aerodynamic, so it is necessary to avoid ice formation on the wings. The hardest condition for ice formation are at altitudes between 10.000 and 15.000 ft and at temperature between 0 °C and -15 °C, because they are particularly suitable for ice formation. In this paper an anti-icing system based on hot air impinging jets on internal wing surface is analyzed in order to check the efficiency of the system. A numerical model is given in order to evaluate the thermal and fluid dynamic behaviours of the impinging jet inside the wing panel. A wing profile with an angle of attack of 4.50° is taken into account with a free stream temperature of 258 K. A piccolo tube with a diameter of 1.00 inch and air temperature of 523 K is considered for anti-icing system. A structured mesh is used in the discretization of the computational domain for the two-dimensional and three-dimensional case. A steady state solution with k-ε RNG turbulent model has been found. Numerical simulations of a two and a three dimensional model of an aircraft wing has been carried out taking into account the external convective exchange by means of an average coefficient on the external surface and thermofluidynamic field inside the wing due to the anti-icing system. The analysis is performed by means of the FLUENT code in order to find the optimal geometrical configuration to avoid the ice formation on the external wing surface. Results are presented in terms of stream function and temperature fields, wall temperature profiles along the wing surfaces and air velocity and temperature profiles.