Aeroelastic scaling for rotary-wing aircraft with applications

P., Freidmann, Peretz

doi:10.2514/6.2001-1534

Cited by 5 publications

(4 citation statements)

References 11 publications

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“…The first challenge encountered with FSI experiments is given by the problem of scaling. While Mach and Reynolds numbers are the most relevant parameters for aerodynamic scaling, FSI problems require consideration of the ratio of fluid and structure inertia alongside the structure relative stiffness (Friedmann 2004;Wan and Cesnik 2014).…”

Section: Introductionmentioning

confidence: 99%

On the closure of Collar’s triangle by optical diagnostics

2022

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An experimental methodology is proposed to study aeroelastic systems with optical diagnostics. The approach locally evaluates the three physical mechanisms that produce the forces involved in Collar’s triangle, namely aerodynamic, elastic, and inertial forces. Flow and object surface tracers are tracked by a volumetric particle image velocimetry (PIV) system based on four high-speed cameras and LED illumination. The images are analysed with Lagrangian particle tracking techniques, and the flow tracers and surface markers are separated based on the different properties of their images. The inertial and elastic forces are obtained solely analysing the motion and the deformation of the solid object, whereas the aerodynamic force distribution is obtained with pressure from PIV techniques. Experiments are conducted on a benchmark problem of fluid–structure interaction, featuring a flexible panel installed at the trailing edge of a cylinder. Data are collected in the resonant regime, where the panel exhibits a two-dimensional motion. The estimation of inertial and elastic forces is obtained enforcing a high-order polynomial fit to the surface motion and deformation. The aerodynamic loads on the panel are challenged by the need to devise adaptive boundary conditions complying with the panel motion. The closure of Collar’s triangle yields overall residuals of about one-half of the inertial force taken as reference. The simultaneous measurement of the three forces paves the way to assessing the equilibrium of forces closing the Collar’s triangle. The latter can be intended for uncertainty evaluation or, when only two forces are measured, for estimation of the remaining Collar element. Graphical Abstract

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Section: Introductionmentioning

confidence: 99%

On the closure of Collar’s triangle by optical diagnostics

2022

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“…From the experimental perspective, the first challenge is given by the problem of scaling. While Mach and Reynolds numbers are the most relevant parameters for aerodynamic scaling, for FSI problems, one needs to consider the ratio of fluid and structure inertia alongside the relative stiffness of the latter (Friedmann, 2004;Wan and Cesnik, 2014).…”

Section: Introductionmentioning

confidence: 99%

Towards the closure of Collar’s triangle by optical diagnostics

Saiz¹,

Sciacchitano²,

Scarano³

2021

ISPIV21

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An experimental methodology is proposed for the study of aeroelastic systems. The approach locally evaluates the forces involved in Collar’s triangle, namely aerodynamic, elastic, and inertial forces. The position of flow tracers as well as of markers on the object surface is monitored by a volumetric PIV system. From the recorded images, the flow tracers and surfare markers are separated based on their optical characteristics. The resulting images are then analysed by Lagrangian particle tracking. The inertial and elastic forces are obtained solely analysing the motion and the deformation of the solid object, whereas the aerodynamic force distribution is obtained via the pressure-from-PIV technique. Experiments are conducted on a benchmark problem of fluid-structure interaction, featuring a flexible panel installed at the trailing edge of a cylinder. A polynomial fit of the markers’ positions is carried out to determine the panel’s instantaneous shape, from which the inertial and elastic forces are evaluated. The pressure loads on the panel are determined via solution of the Poisson equation for pressure, imposing adaptive boundary conditions that comply with the panel. The simultaneous measurement of the three forces allows to assess the equilibrium of forces, and in turn to close Collar’s triangle.

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“…An advanced beam-wise equivalent model has been developed in the following on the basis of available literature and assumptions (Tang and Dowell, 2001;Cestino, 2006;Romeo et al, 2006;Frulla and Cestino, 2010a;Frulla et al, 2010b). Up to second-order terms that are valid in a moderate-to-large deflection range (no higher than 10 per cent of the wing span) have been considered in the structural derivation (Friedmann, 2004;Friedmann et al, 2009). Assumptions on the shear flow (constant) and negligibility of the circumferential stress resultant have been introduced into the derivation.…”

Section: Introductionmentioning

confidence: 99%

Analysis of slender thin-walled anisotropic box-beams including local stiffness and coupling effects

Cestino

Frulla

2014

Aircraft Eng & Aerospace Tech

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Article information:To cite this document: Enrico Cestino Giacomo Frulla , (2014),"Analysis of slender thin-walled anisotropic box-beams including local stiffness and coupling effects", Aircraft Engineering and (2014),"A robustness-based design strategy for composite structures -probabilistic approach", Aircraft Engineering and Aerospace Technology, Vol. 86 Iss 4 pp. 262-273 http://dx.(2014),"A robustness-based design strategy for composite structures", Aircraft Engineering and Aerospace Technology, Vol. 86 Iss 4 pp. 274-286 http://dx.If you would like to write for this, or any other Emerald publication, then please use our Emerald for Authors service information about how to choose which publication to write for and submission guidelines are available for all. Please visit www.emeraldinsight.com/authors for more information. About Emerald www.emeraldinsight.comEmerald is a global publisher linking research and practice to the benefit of society. The company manages a portfolio of more than 290 journals and over 2,350 books and book series volumes, as well as providing an extensive range of online products and additional customer resources and services.Emerald is both COUNTER 4 and TRANSFER compliant. The organization is a partner of the Committee on Publication Ethics (COPE) and also works with Portico and the LOCKSS initiative for digital archive preservation. AbstractPurpose -This study aims to analyse slender thin-walled anisotropic box-beams. Fiber-reinforced laminated composites could play an important role in the design of current and future generations of innovative civil aircrafts and unconventional unmanned configurations. The tailoring characteristics of these composites not only improve the structural performance, and thus reduce the structural weight, but also allow possible material couplings to be made. Static and dynamic aeroelastic stability can be altered by these couplings. It is, therefore, necessary to use an accurate and computationally efficient beam model during the preliminary design phase. Design/methodology/approach -A proper structural beam scheme, which is a modification of a previous first-level approximation scheme, has been adopted. The effect of local laminate stiffness has been investigated to check the possibility of extending the analytical approximation to different structural configurations. The equivalent stiffness has been evaluated for both the case of an isotropic configuration and for simple thin-walled laminated or stiffened sections by introducing classical thin-walled assumptions and the classical beam theory for an equivalent system. Coupling effects have also been included. The equivalent analytical and finite element beam behaviour has been determined and compared to validate the considered analytical stiffness relations that are useful in the preliminary design phase. Findings -The work has analyzed different configurations and highlighted the effect of flexural/torsion couplings and a local stiffness effect on the global behaviour of the structure. Three types of...

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Aeroelastic scaling for rotary-wing aircraft with applications

Cited by 5 publications

References 11 publications

On the closure of Collar’s triangle by optical diagnostics

On the closure of Collar’s triangle by optical diagnostics

Towards the closure of Collar’s triangle by optical diagnostics

Analysis of slender thin-walled anisotropic box-beams including local stiffness and coupling effects

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