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Study of transition location effect (from natural transition to fully turbulent) on separation size, shock structure and unsteadiness was the focus of this WP. Boundary layer tripping (by wire or roughness) and flow control devices (VG) were used for boundary layer transition induction. Although this type of flow field had been studied widely in the past, there remains considerable uncertainty on the effects of transition on transonic aerofoil performance. In particular it is not known how close to the shock location transition has to occur to avoid detrimental effects associated with laminar shock-induced separation. Furthermore, it was unclear how best to provoke transition on an airfoil featuring significant laminar flow and how close to the shock this needs to be performed. Finally, current CFD methods are particularly challenged by such transitional flows. In this work package some of the findings from the basic research performed in other WPs was applied. Specialized large-scale transonic wind tunnels running cost is very high therefore using such facilities is not appropriate for upstream research programs such as TFAST. Therefore we have used existing wind tunnels within our consortium. One of these is a transonic test section at UCAM where laminar and transitional profiles were studied previously at Reynolds numbers up to 2 million (based on chord length). This wind tunnel allowed basic investigations of the transition location effects on a shock induced separation and unsteadiness for a relatively large number of parameters. A larger wind tunnel at Institute of Aviation in Warsaw was used, which enabled the investigation of a much larger aspect ratio profile. In this facility it was possible to measure a whole force polar up to and including the buffet boundary. The research was carried out for the natural b/l transition location as well as different methods of tripping.

Purpose The purpose of this paper is to present the methodology and approach adapted to conduct a wind tunnel experiment on the inverted joined-wing airplane flying model together with the results obtained. Design/methodology/approach General assumptions underlying the dual-use model design are presented in this paper. The model was supposed to be used for both wind tunnel tests and flight tests that significantly drive its size and internal structure. Wind tunnel tests results compared with the outcome of computational fluid dynamics (CFD) were used to assess airplane flying qualities before the maiden flight was performed. Findings Extensive data about the aerodynamic characteristics of the airplane were collected. Clean configurations in symmetric and asymmetric cases and also configurations with various control surface deflections were tested. Practical implications The data obtained experimentally made it possible to predict the performance and stability properties of the unconventional airplane and to draw conclusions on improvements in further designs of this configuration. Originality/value The airplane described in this paper differs from frequently analyzed joined-wing configurations, as it boasts a front lifting surface attached at the top of the fuselage, whereas the aft one is attached at the bottom. The testing technique involving the application of a dual-use model is also innovative.

Wind tunnel tests of a laminar airfoil have been performed at the Institute of Aviation in Warsaw. The main goal of the investigation was to study the separation process development in subsonic and early transonic flow regime. The airfoil chord was 0.2m. During wind tunnel test the natural laminar-turbulent transition was applied. The Mach numbers were 0.3 and 0.7. Reynolds number were approximately equal to 1.22.106 and 2.85.106 respectively. The angle of incidence was increased up until the flow was fully separated. During the experimental research, chosen test methods such as pressure measurements and schlieren visualization were applied. Wind tunnel results were analyzed in terms of aerodynamic coefficients and flow separation type identification. The wind tunnel investigation revealed that separation phenomena at subsonic and transonic flow regime affected in a different manner on the airfoil aerodynamic performance. This was mainly because of the change of the flow pattern influencing on the separation process.

The paper presents results of wind tunnel tests of the Experimental Rocket Platform (ERP), which is developed in Institute of Aviation. It is designed as an easy accessible and affordable platform for microgravity experiments. Proposed design enables to perform experiments in microgravity for almost 150 seconds with apogee of about 100 km. The full-scale model of the ERP has been investigated in the T-3 wind tunnel in Institute of Aviation. During the investigation, the aerodynamic loads of the rocket has been measured for the angle of attack up to 10° and the different rotation angle around the longitudinal axis (up to 90°, depending on the configuration). Three configurations has been investigated: • without fins and boosters • with fins and without boosters • with fins and boosters Additionally, the measurements of velocity field around the ERP using the Particle Image Velocimetry (PIV) has been performed. Based on the wind tunnel test, an influence of fins and boosters on aerodynamic characteristics of the rocket has been described. Results of the wind tunnel tests show relatively high contribution of boosters in total aerodynamic drag. Some conclusions concerning performance and stability of the rocket have been presented.