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Numerical Modelling of Static Aeroelastic Deformations of Slender Wing in Aerodynamic Design

Bugała Pamela, Sznajder Janusz, Sieradzki Adam

Transactions on Aerospace Research

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2023

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Nr 4 (273)

52--70

EN

The article presents the validation of two methods for analyzing the aerodynamic properties of the aircraft wing concerning aeroelastic effects. The first method is based on low-cost computational models (Euler-Bernoulli Beam Model and Vortex Lattice Method [VLM]). Its primary objective is to estimate the wing’s deformation early in the design stages and during the automatic optimization process. The second one is a method that uses solutions of unsteady Navier-Stokes equations (URANS). This method suits early design, particularly for unconventional designs or flight conditions exceeding low-fidelity method limits. The coupling of the flow and structural models was done by Radial Basis Functions implemented as a user-defined module in the ANSYS Fluent solver. The structural model has variants for linear and nonlinear wing deformations. Features enhancing applicability for real-life applications, such as the definition of deformable and nondeformable mesh zones with smooth transition between them, have been included in this method. A rectangular wing of a high-altitude long-endurance (HALE) aeroplane, built based on the NACA 0012 profile, was used to validate both methods. The resulting deflections and twists of the wing have been compared with reference data for the linear and nonlinear variants of the model.

2

Airfoil Tonal Noise Prediction Using Urans

Klimczyk Witold, Sieradzki Adam

Transactions on Aerospace Research

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2023

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Nr 4 (273)

1--17

EN

To examine the feasibility of the laminar boundary layer (LBL), vortex shedding (VS) tonal noise modelling using unsteady Reynolds-averaged Navier-Stokes (URANS) was investigated for the non-symmetric S834 airfoil. A transition SST turbulence model was used to model the laminar-turbulent transition and its vital influence on the laminar bubble and hydrodynamic instabilities generation. The influence of turbulence on the unsteady vortex patterns was investigated. Hence, the hybrid aeroacoustic analysis with Lighthill analogy was conducted to obtain the acoustic pressure field. The approach allowed us to model hydrodynamic instabilities and the resulting VS tonal noise. The frequency of VS matched the experimental data, giving the same 1/3 octave tonal peak only for a limited freestream turbulence regime. The simplification of the present method did not allow us to model the aeroacoustic feedback loop, and resulted in lack of instabilities for higher freestream turbulence.

3

Method of Designing a Distortion Gauze for Testing a Boundary Layer Ingesting Fan

Kwiatkowski Tomasz, Sieradzki Adam, Łukasik Borys

Transactions on Aerospace Research

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2022

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Nr 1 (266)

1--17

EN

As global trends aim to reduce emissions of pollutants, boundary layer ingesting (BLI) propulsions are attracting more and more attention. As such, N+2 generation aircraft with propulsion placed in the aft of the aircraft are gaining in popularity. The boundary layer is formed on the fuselage before entering the engine located in the aft of the aircraft. Due to significant difficulties in performing experimental tests of BLI propulsors with full-size aircraft, distortion gauzes are one of the methods to provide the desired air velocity profile at the inlet. This paper describes a novel method of designing such gauzes, a topic which is not well covered in the existing literature. In the first stage of the presented method, single orifices of different sizes were calculated using CFD tools. The relationship between their size and the gauze resistance coefficient was identified, making it possible to model the distortion gauze using porous media. An iterative approach was used to design a gauze that meets the requirements. This is, to our knowledge, the first distortion gauze design description where a porous media model has been used. Experimental tests demonstrated that the produced distortion gauze yields a velocity profile comparable to the desired one. This indicates the great potential of using the presented approach in further research on boundary layer ingesting propulsions. It offers an opportunity to reduce substantially both the costs of experimental research and the time required to design a distortion-tolerant fan.