27 TH INTERNATIONAL CONGRESS OF THE AERONAUTICAL SCIENCES 1 Abstract In this paper we try to introduce CFD to an unconventional place: the wind tunnel. The aim of this paper is to study the aerodynamic interference effects of two different stings supporting an aircraft model during wind tunnel tests. The flow field and forces distortion caused by the stings were deduced by comparing simulations with and without support. Comparison against experimental measurements thanks to dummy sting tests is provided for validation purpose. 1 Introduction During wind tunnel tests the aircraft model is maintained in the test section thanks to a support system. This support is shaped to be as small and as discrete as possible, under the constraint that it should sustain forces generated over a wide range of flow conditions and enclose all cables and tubes necessary to supply energy and collect measurements from the embarked sensors. Several recent ([1][3]) or older ([6]) initiatives aimed at determining whether advanced numerical simulations could help in understanding and predicting the support interference effect. This paper summarizes such an attempt carried out at ONERA on a transonic transport aircraft. 2 Description of experimental tests and numerical simulations 2.1 Model and supports The aircraft model selected for this study was a full aircraft comprising the fuselage, the wing with four nacelles (non-powered), the vertical and horizontal tail planes (VTP and HTP). The wing shape is representative of state of the art aerodynamic design for this kind of civil aircraft. The wind tunnel supports under study in this paper are: • a straight sting made of cylindrical and conical pieces and penetrating the aircraft fuselage from behind, near the horizontal tail plane; • a Z-sting, mainly composed of a conical sting supporting a blade which itself penetrates the rear fuselage of the model from below. Those two supports and the model are presented in Fig. 1. Fig. 1. View of the model and the supports. 2.2 Wind tunnel tests This model was tested in S1MA wind tunnel in 2003, during an entry dedicated to the measurement of support effects. To serve that purpose, the model was mounted on a twin STUDY OF SUPPORT INTERFERENCE EFFECTS AT S1MA WIND TUNNEL WITHIN THE “SAO” PROJECT Aurélia Cartieri, S. Mouton, G. Boyet ONERA Keywords: aerodynamics, wind tunnel, support interference