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Zhukovsky, Russia

Dubovikov E.,TsAGI
27th Congress of the International Council of the Aeronautical Sciences 2010, ICAS 2010 | Year: 2010

The results of new algorithm's validations are presented for composite wing optimization procedure taking into account constraints on structure elasticity characteristics. Optimal strength and stiffness parameters of the composite wing are determined by using: 1. Analytical beam model of the wing; 2. Parametrical finite element model of the airframe structure; 3. Statistical techniques for correction of the structure weight; At the first stage the problem of weight optimization is solved in frames of the classical beam model. Optimal values of stiffnessparameters obtained from the optimization are transferred to the data base of FEM model. Additional constrains on a stiffness of finite elements are generated there basing on these values.It was shown during the calculations these constrains were active for lateral parts of wings.Then the classical (in frames of FEM model) problem is solved for determination of optimal structure parameters to satisfy minimum weight criteria. At the last stage a refinement of the wing structure weight is performed using a database of statistical correction factors. The useofsuch algorithm at initial stage of designing enabled: • to reduce significantly work duration and efforts required for calculating the influence of aeroelastics on strength and weight parameters; • to obtain confident estimations of the influence of elastics on the structure weightin frames of linear FEM models. Validation of the algorithm was carried out in frames of NACREproject of 6th EC Program for estimating weight of composite flying wing structure. The results are presented for optimizing of: • composite wings of high aspect ratio; • wings with critical areas in interfaces to fuselage zones; • wings with large cutouts. Source

Bryantsev B.D.,TsAGI
International Forum on Aeroelasticity and Structural Dynamics, IFASD 2015 | Year: 2015

A brief background on Frequency Response Functions (FRFs) measurement technology applied to mechanical systems on the basis of imposed motion method (kinematic excitation method) is presented herein. Shown is the possibility to use analysis to evaluate an effect of adding extra concentrated mass, stiffness and damping, in the points of application of driving forces, on the FRFs of a tested article with use of experimental FRFs of initial unmodified structure as a reference. The capabilities of the technology for flutter research are demonstrated by the example of GVT of a dynamically-scaled model of an all-movable stabilizer intended for flutter wind tunnel tests, with an electro hydraulic actuator used to impose model displacement in the driving point. The test techniques, as well as details of measuring FRFs under wind tunnel flow conditions with the use of specific multi-sine test signal for structure excitation are described. Presented are examples of measured in-flow model FRFs, and identified modal data as a function of flow parameters, including eigenfrequencies, eigendamping and eigenmodes recovered for unmodified model (free of the links imposed by the actuator) at flow speed beyond flutter boundary. Source

Voyevodin A.V.,TsAGI
29th Congress of the International Council of the Aeronautical Sciences, ICAS 2014 | Year: 2014

This paper deals with computational and experimental aerodynamic studies of a small business jet designed for 4-8 passengers. The novel layout with drop-shaped fuselage provides considerable improvement of passenger comfort and achievement of maximum flight speed, corresponding to Mach number M = 0.8 even with simple straight wing. An aerodynamic model of the airplane has been designed, manufactured and tested in TsAGI wind tunnels. The results of the experimental studies alongside with accompanying detailed CFD calculations which were initiated to clarify the physics of a flow at high velocities and high angles of attack are presented. The paper concludes with suggestions for the possibilities of improving the configuration and proposals for future research. Source

Tsyganov A.P.,TsAGI
29th Congress of the International Council of the Aeronautical Sciences, ICAS 2014 | Year: 2014

The "flying wing"(FW) configuration is one of the most promising alternatives to conventional "tube and wing" scheme. New concept of moderate capacity long-range FW aircraft is investigated in TsAGI over the last years. Various arrangements have been studied with different passenger accommodation, engine positions, control system architecture, etc. Special aerodynamic model with flexible arrangement of tail units, wing tips and nacelles has been tested in several wind tunnels. This paper presents some results of the experimental studies alongside with accompanying CFD results. Source

Skomorohov S.I.,TsAGI
29th Congress of the International Council of the Aeronautical Sciences, ICAS 2014 | Year: 2014

One of the promising ways to increase aerodynamic effectiveness of the advanced civil aircraft assumes an introduction of the so-called adaptive wings which can alter their geometry depending on the flight condition. In spite of a large number of publications and patents concerning adaptive wings there is no established point of view upon both the possible benefits of wing adaptation for transonic transports and the procedure of its in-flight utilization. This paper deals with applied theoretical and practical aspects of wing adaptation for the next generation of transonic airliners. An aerodynamic optimization algorithm was used to assess an adaptive wing concept for drag reduction at transonic speeds. Full adaptation wing concept assess was done through solving a sequence of single point optimization problems, while multi-point optimization procedure was used for justification of partially adapted wings. A new way of using adaptation advantages is proposed by taking modest speed shockless wing as a basic one and trying to mitigate sharp drag rise at off-design regimes with the aid of partial adaptation. Source

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