Optimisation d'un système d'antigivrage à air chaud pour aile d'avion basée sur la méthode du krigeage dual

Abstract

The aim of this thesis is to apply a new methodology of optimization based on the dual kriging method to a hot air anti-icing system for airplanes wings. The anti-icing system consists of a piccolo tube placed along the span of the wing, in the leading edge area. The hot air is injected through small nozzles and impact on the inner wall of the wing. The objective function targeted by the optimization is the effectiveness of the heat transfer of the anti-icing system. This heat transfer effectiveness is regarded as being the ratio of the wing inner wall heat flux and the sum of all the nozzles heat flows of the anti-icing system. The methodology adopted to optimize an anti-icing system consists of three steps. The first step is to build a database according to the Box-Behnken design of experiment. The objective function is then modeled by the dual kriging method and finally the SQP optimization method is applied. One of the advantages of the dual kriging is that the model passes exactly through all measurement points, but it can also take into account the numerical errors and deviates from these points. Moreover, the kriged model can be updated at each new numerical simulation. These features of the dual kriging seem to give a good tool to build the response surfaces necessary for the anti-icing system optimization. The first chapter presents a literature review and the optimization problem related to the antiicing system. Chapters two, three and four present the three articles submitted. Chapter two is devoted to the validation of CFD codes used to perform the numerical simulations of an anti-icing system and to compute the conjugate heat transfer (CHT). The CHT is calculated by taking into account the external flow around the airfoil, the internal flow in the anti-icing system, and the conduction in the wing. The heat transfer coefficient at the external skin of the airfoil is almost the same if the external flow is taken into account or no. Therefore, only the internal flow is considered in the following articles. Chapter three concerns the design of experiment (DoE) matrix and the construction of a second order parametric model. The objective function model is based on the Box-Behnken DoE. The parametric model that results from numerical simulations serve for comparison with the kriged model of the third article. Chapter four applies the dual kriging method to model the heat transfer effectiveness of the anti-icing system and use the model for optimization. The possibility of including the numerical error in the results is explored. For the test cases studied, introduction of the numerical error in the optimization process does not improve the results. Dual kriging method is also used to model the distribution of the local heat flux and to interpolate the local heat flux corresponding to the optimal design of the anti-icing system.

Date	21 Feb 2014
Original language	French
Awarding Institution	École de technologie supérieure
Supervisor	François Morency (Supervisor)