Search for: high-aspect-ratio-wing
Viscous damping effect on the aeroelastic stability of subsonic wings: Introduction of the U–K method, Article Journal of Fluids and Structures ; Volume 73 , 2017 , Pages 1-15 ; 08899746 (ISSN) ; Dehghani Firouz Abadi, R ; Rahmanian, M ; Sharif University of Technology
This study aims at introduction of a novel method for evaluating the effect of viscous damping on the aeroelastic stability boundaries. The K-method is well-known for being one of the fastest methods in determining the instability conditions (i.e. critical speed and its corresponding frequency). However, formulation of the K-method is developed for aeroelastic systems without viscous damping and solution is valid where the introduced artificial damping is zero. Taking into account the framework of the K-method in general, this study has tried to remove the major shortcoming of the K-method, i.e. investigation of the effect of viscous damping on the aeroelastic stability boundaries. The...
Article Nonlinear Dynamics ; Volume 67, Issue 1 , 2012 , Pages 659-681 ; 0924090X (ISSN) ; Sadr, M. H ; Haddadpour, H ; Sharif University of Technology
This paper aims the nonlinear aeroelastic analysis of slender wings using a nonlinear structural model coupled with the linear unsteady aerodynamic model. High aspect ratio and flexibility are the specific characteristic of this type of wings. Wing flexibility, coupled with long wingspan can lead to large deflections during normal flight operation of an aircraft; therefore, a wing in vertical/forward-afterward/torsional motion using a third-order form of nonlinear general flexible Euler-Bernoulli beam equations is used for structural modeling. Unsteady linear aerodynamic strip theory based on the Wagner function is used for determination of aerodynamic loading on the wing. Combining these...
Article Journal of the Brazilian Society of Mechanical Sciences and Engineering ; Volume 42, Issue 11 , 2020 ; Roudbari, A ; Hajipourzadeh, P ; Sharif University of Technology
Springer Science and Business Media Deutschland GmbH 2020
In this paper, a new approach for multi-objective robust optimization of flutter velocity and maximum displacement of the wing tip are investigated. The wing is under the influence of bending–torsion coupling and its design variables have different levels of uncertainty. In designing and optimizing wings with a high aspect ratio, the optimization process can be done in such a way to increase the flutter velocity, but this can increase the amplitude of the wing tip displacement to a point that leads to the wings damage and structural failure. Therefore, single-objective design optimization may lead to infeasible designs. Thus, for multi-objective optimization, modeling is based on the...