Computational fluid dynamics is employed to evaluate the mean aerodynamic loading on the retractable landing-gears of a regional transport commercial aircraft. The mean turbulent flow around simplified landing-gear systems including doors is simulated by using the Reynolds-averaged Navier–Stokes approach, where the governing equations are solved with a finite volume-based numerical method. Using a dynamic meshing method, the computational grid is automatically and continuously adapted to the time-changing geometry, while following the extension/retraction of the landing-gear systems. The temporal evolution of the aerodynamic forces on both the nose and the main landing-gears, along with the hinge moments of the doors, is numerically predicted. The proposed computational modeling approach is verified to have good practical potential when compared with reference experimental data provided by the Leonardo Aircraft structural loads group.

https://www.mdpi.com/2226-4310/7/6/68/pdf

Computational Evaluation of Aerodynamic Loading on Retractable Landing-Gears

In this paper, rotors with artificial iced shapes are studied to develop insight in the potential of acoustics-based ice detection. Using the Helicopter Multi-Block CFD solver, approximate iced shapes are added to the blades and the results are analyzed using the FW-H method. Several candidate monitoring positions are assessed for acoustic sensors to be placed on the helicopter fuselage. The influence of ice on the aero-acoustic characteristics of a rotor is calculated, and parameters such as the ice amount and the icing position on the blade are quantified.

/pdf/numerical-analysis-of-hovering-main-rotor-aero-acoustic-2mee7p8zs5.pdf

Numerical analysis of hovering main rotor aero-acoustic characteristics for ice detection

Purpose of research is to develop a method for accounting for the influence of end washers on the flow of wings with an arbitrary distribution of fillets over the span. Methods . The installation of end washers significantly improves the aerodynamics of the wing, increasing lift and reducing inductive resistance. The theory of a continuous vortex surface is applied to simulate the effect of end washers on the flow of a volumetric wing. In accordance with it, oblique horseshoe-shaped vortices that model the upper and lower sides of the wing are continuously distributed along the longitudinal panels, into which the half-span of the wing is divided. The bearing parts of each horseshoe-shaped vortex lie in planes parallel to the plane of the wing chords and pass through the points and the middle section of the panel at which the induced velocities are calculated. The free vortices of the wing descend from its ends from the upper and lower surfaces at an angle to the plane of the chords. Results . An algorithm has been developed for calculating the intensity of vortices from the non-permeability condition, taking into account the attached and free vortices of the wing and the end-washer vortices. The vortex densities included in this condition are represented by trigonometric series. The developed method takes into account the geometry of the profile and end washers, the shape of the wing in the plan. The vortices induce an additional velocity at the points on the surface of the wing. To calculate their values, the Biot-savard formula on vortex influence is used. Conclusion . A method for calculating the aerodynamic characteristics of a volumetric wing with end washers has been developed from the unified positions of the theory of a continuous vortex surface. The calculations take into account the geometry of the washers and profile, the shape of the wing in the plan. The method is universal and can be used for wings without washers, including for thin ones.

/pdf/metod-uchiota-vliianiia-kontsevykh-shaib-na-obtekanie-kryla-1cvnmcew4k.pdf

Метод учёта влияния концевых шайб на обтекание крыла с изменяющимися по размаху профилями

CFD analysis is carried out to evaluate the mean aerodynamic loads on the retractable main landing-gear of a regional transport commercial aircraft. The mean flow around the landing-gear system including doors is simulated by using the Reynolds-averaged Navier-Stokes modelling approach, the governing equations being solved with a finite volume-based numerical technique. The computational grid is automatically adapted to the time-changing geometry by means of a dynamic meshing technique, while following the deployment of the landing-gear system. The present computational modelling approach is verified to have good practical potential by making a comparison with reference experimental data provided by the Leonardo Aircraft Company aerodynamicists.

CFD Prediction of Retractable Landing Gear Aerodynamics

Numerical investigation of the hinge moments of the nose landing gear doors in a passenger aircraft in the process of opening

Determining hinge moments of the main landing gear fuselage door by means of numerical flow simulation

The influence of the wingtip on airflow past a wing

https://dl.begellhouse.com/download/article/0cc26077784950fb/TsAGI4002 (207-216).pdf

Parametric investigations of the effect of icing on the aerodynamic characteristics of a wing airfoil

https://robots.iopscience.iop.org/article/10.1088/1757-899X/904/1/012015/pdf

Olga Viktorovna Pavlenko

Papers

Numerical investigation of the hinge moments of the nose landing gear doors in a passenger aircraft in the process of opening

Determining hinge moments of the main landing gear fuselage door by means of numerical flow simulation

The influence of the wingtip on airflow past a wing

Parametric investigations of the effect of icing on the aerodynamic characteristics of a wing airfoil

Influence of interference between the fuselage and the propeller ring on the maximum thrust of the air pusher propeller