Comprehensive assessment of the strength of the composite fan blade of the main ventilation of the mine

The work is devoted to the development and calculation of the strength of a new composite fan blade of the main ventilation of the mine, including the static and modal analyzes, as well as the stability analysis. The studies took into account the pre-determined aerodynamic loads on the lateral surface of the blade airfoil. The research was carried out by means of the finite element analysis of the thin-walled airfoil structure using the theory of thick multilayer shells. Estimation of the static strength was performed using the Hashin strength criterion. Analysis of the airfoil shell buckling resistance under the action of bending aerodynamic loads was performed using the methods of the linear stability theory. The modal analysis was performed taking into account the prestressed state from the action of static loads. The analysis of the research results testifies to the sufficient static and dynamic strength of the composite airfoil and the possibility of its implementation in a real rotary machine with the correct design of the fastening between the metal part of the blade root and the composite airfoil. The method of designing and analyzing the strength of the fan blade composite airfoil can be used to create new composite elements of turbomachines: the correct selection of thicknesses of different parts of the airfoil allows obtaining a uniform design with rational use of material; the optimal location of the stiffeners inside the airfoil shell avoids its excessive displacement and stress and the buckling effects, as well as achieving the maximal detuning level from the bending natural frequencies of vibrations; the proposed integrated approach to the strength assessment, which takes into account the effect of aerodynamic loads on the blade airfoil in the static analysis and the prestressed state during the modal analysis can significantly improve the accuracy and correctness of calculations. The approach described in the paper is new for low-speed rotary machines, as at present there are no comprehensive methods for designing composite blades of fans and compressors, and there is no mention of specific examples of their implementation in the projects implemented by manufacturers.

Software complex for aircraft characteristics calculation

The article describes the method of calculating the aerodynamic loads of the aircraft, which can be programmed within the graphic user interface. The method uses statistical data of typical aerodynamic profiles flow in wind tunnels and mathematical expressions that describe the known laws of aerohydromechanics. The graphic user interface is tested by a model of the famous Ukrainian aircraft A32 that manufactured by Aeropract company. A surface model of the aircraft for modeling consists of the theoretical surface for the wing and the fuselage. A comparison of the formula’s calculation in the graphical interface and finite element calculations is given. The software interface is built in C #.

Design, fabrication, and testing of an active camber rotor blade tip

This paper presents a morphing blade design for wind turbine application with flexibility in chord-wise bending while providing sufficient stiffness to carry the aerodynamic loads. The NACA64 profile is selected for the camber morphing blade demonstrator. A corrugation concept is chosen because it is relatively easy to manufacture and provides sufficient stiffness to resist deformation due to the aerodynamic loads (through the provision of effective stringers) while providing the required flexibility for chord-wise bending. A mechanical actuation mechanism is employed to achieve the desired morphing angle and increase the stiffness of the morphing airfoil section to resist aerodynamic loading. The design of a morphing blade demonstrator is presented together with the manufacturing process. Finally, an experimental study is conducted where the morphing angle is measured for increasing actuation load and compared with FE analysis showing good agreement between the experimental results and results from the finite element analysis in addition to achieving the desired morphing angle.

Aero-Structural Coupling Strategy for a Morphing Blade Cascade Study

The coupling of aerodynamics and structural mechanics is an important step in the design process of aeronautical devices with morphing parts. In this paper, a 2D-3D coupling approach is developed to study a morphing blade cascade. Two shape memory alloy actuators are placed on the upper and lower sides of the blade to make possible the change in shape of the leading-edge. In the present work, a preliminary design study is conducted by considering a two-dimensional CFD analysis of an airfoil cascade coupled with a three-dimensional structural analysis of the whole 3D blade. A methodology is developed to match 2D and 3D meshes such that the aerodynamic loads can be easily transferred to the structural analysis. From there, the deformed blade geometry due to both aerodynamic loads and actuator work can be transferred back to the CFD solver, and the iterative aero-structural coupling loop can be repeated until convergence. The aero-structural coupling strategy developed in this work is also applied to a blade cascade study aiming to improve its performance by morphing the leading-edge of the blade. The results of this application show that by morphing the leading-edge blade of only few millimeters (less than 2 mm), it is possible to achieve a relevant performance improvement in terms of total pressure loss coefficient decrease of about 53%.

Morphing Winglet Design for Aerodynamic Performance Optimization of the CRJ-700 Aircraft. Part 1 – Structural Design

This study aims to design a morphing winglet structure for the CRJ-700 regional transport aircraft. The morphing technology is applied on winglets to demonstrate a significant increase of the aerodynamic performance of aircraft. From the aerodynamic data of the LARCASE Virtual Research Simulator VRESIM, the aerodynamic benefits in the cruising phase were obtained through a study on the ParaView software. The morphing winglet design was drawn using CATIA V5; this new concept included several structural components, as well as a simple and light mechanism allowing to orientate the winglet angles between 90° and -90° of inclination. The structural model was exported to HyperMesh structural analysis software. Maximum stresses were obtained, and the model demonstrated its resistance to maximum aerodynamic loads as well as load factors of -2G to 7G.

Multiscale Simulation of Temperature- and Pressure-dependent Nonlinear Dynamics of PMMA/CNT Composite Plates

Owing to the excellent mechanical properties, polymethyl methacrylate (PMMA)/carbon nanotube (CNT) composite has been increasingly adopted in the aerospace field, which is usually subjected to various temperature conditions and supersonic aerodynamic loads. Using a molecular dynamics (MD)-based multiscale simulation, the nonlinear forced vibration of PMMA/CNT composite plate is investigated under coupled temperature and aerodynamic loads conditions. The longitudinal, transverse, and shear moduli of PMMA/single-walled CNT (SWCNT) nanocomposite obtained from MD simulation at different temperature and pressure levels are substituted into the extended rule of mixtures to establish the constitutive equations of PMMA/CNT composite plate. Meanwhile, Poisson’s ratio and thermal expansion coefficient of nanocomposite are used in the constitutive equations. Based on the third-order shear deformation theory, von-Karman nonlinear strain-displacement relation, and Hamilton’s principle, the partial differential equation of composite plate is derived, which is reduced into a set of coupled ordinary differential equations by applying Galerkin method and is solved using the fourth-order Runge-Kutta method. The phase portraits and time histories of composite plate are obtained under the complex loads including transverse harmonic excitation and aerodynamic pressure, which are applied to analyze the dynamic characteristics of system. This study reveals the nonlinear dynamic characteristics of PMMA/CNT composite plate, which contributes to the prediction of long-term performance of composite materials in aerospace field.