Interview 5

Vitaly Soudakov, Head of Group, Aerodynamics Department

Natalia Miroshnichenko, Head of Project Development Group, International Business Department

Central Aerohydrodynamic Institute (TSAGI)

Q1: The objective of the activities in which TSAGI is mainly involved is to prove the Technology Readiness Level (TRL) 4 for the Active Flow Control (AFC) at the Engine-Wing junction. What were the steps required prior to the validation in large-scale Wind Tunnel (WT) tests?

V. Soudakov: The main steps prior to WT tests are design and manufacturing of large-scale WT model that is suitable for the representation of the typical flow separation phenomena near the junction of Ultra High Bypass Ratio (UHBR) engine with the wing. This flow separation should be obtained in WT tests at low speed and high angles of attack for landing or take-off configurations. The baseline WT model consists of 2.5D swept wing with the DLR F15 airfoil in high-lift configuration. Sweep angle of the leading edge is 28º. The model includes also underwing mounted UHBR flow-through-nacelle attached to the wing by a pylon.

To reduce or suppress the separation AFC hardware were developed by partners. The next important step is the integration of AFC hardware into WT model together with corresponding equipment for WT tests. Two actuators with aircraft scale will be considered: pulsed jet actuator developed by Airbus and synthetic jet actuator developed by Fraunhofer and NLR. For pulsed jet actuator, compressed air will be supplied with stagnation pressure up to 6 atm and mass flow rate up to 5 kg/s.

Q2: What are the activities performed by TSAGI in regard with the wind tunnel model? What are the characteristics (Rn, size) of the TSAGI WTT facility?

V. Soudakov: The main difficulty with manufacturing of the WT model is a very big size of the model. For example, the mean aerodynamic chord (MAC) of the model is 3.259 m. The spanwise size of the model is approximately 6 m. WT test will be carried out in TsAGI T-101 facility (Fig. 2). T-101 is a subsonic continuous-operation, closed-layout wind tunnel with two reverse channels and an open test section. Two fans of total power 30 MW generate the flow. Test section of T-101 has elliptic cross section with axes 2414 m and length 24 m. Flow velocity is up to 50 m/s. WT T-101 and the model allow to investigate actuation concepts at realistic scale and at industrially relevant flow conditions given by Reynolds number 11.4 Mio based on MAC and Mach number M=0.15 that allow to prove TRL=4 for considered AFC technologies.

Q3: You plan on perform possible measurements during the wind tunnel test. What techniques have you envisaged and how have your prepared the test matrix?

V. Soudakov: T-101 WT is equipped with a six-component electro-mechanical balance and different visualization techniques. The following measurements will be performed during WT tests: measurement of free-stream parameters and parameters of supplied compressed air; pressure measurements on the model surface (~400 points); balance measurements. Visualization by mini-tufts in the region of possible separation will be also performed. Moreover, special technique for surface streamlines visualization will be applied – particle image surface flow visualization (PISFV) to clarify presence or reduction of the separation due to application of AFC systems. All these techniques were integrated into test-matrix prepared by DLR and TsAGI for WT tests.

Q4: In AFLoNext TSAGI is one of the partners involved within the international cooperation with the EU. Could you tell us the benefits of such a participation? Have you (or any of the AFLoNext partners) taken any special steps to ensure TSAGI good integration in the project work plan, different activities and exchange of information and knowledge?

N. Miroshnichenko: TsAGI has a long-term history of participation in projects of European Framework Programmes. The benefits of such participation is that TsAGI is getting involved in world-class aeronautics research developments, our specialists have the possibility to exchange advanced ideas with European researches and young scientists get unique experience in working in cooperation with European partners. Our good integration in the project is ensured by the excellent team of project partners as well as by TsAGI capabilities in aeronautics research and large experience in participation in EU-funded projects.