Flutter Tests of the Pazy Wing

Drachinsky, Ariel; Avin, Or; Raveh, Daniella E.; Ben-Shmuel, Yaron; Tur, Moshe

doi:10.2514/6.2022-2186

Cited by 7 publications

(9 citation statements)

References 4 publications

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“…Ignoring the second torsion mode, the results shown in Fig. 9 are very similar to experimental data shown in [4].…”

Section: Flutter Characteristicssupporting

confidence: 85%

“…Figure 9 shows the same analysis on the first bending mode. Consistent with the experimental analysis [4], the vertical displacement (which is changing signs around 85% of the span) corresponds to the second bending mode and is in phase with the twist, and ahead of it (as evidenced by the trough for 𝑤 − w at 𝑡𝑈 ∞ /𝑐 = 516 and the trough for 𝜃 at 𝑡𝑈 ∞ /𝑐 = 517). Again the horizontal motion seems to follow the twist.…”

Section: Flutter Characteristicssupporting

confidence: 84%

“…Note that from here on, 𝜃 is simply the angle around the 𝑦 axis, as computed by the structural model, hence ignoring the small contribution from rotation around the 𝑧 axis. The Pazy flutter boundaries were measured by recent experiments [4] where two regions could be extracted: a smaller onset region and a larger offset region. For example, at 3 deg, if the flow speed was continuously increased, the wing would start vibrating at 49 m/s.…”

Section: B Aeroelastic Simulations Validationmentioning

confidence: 99%

“…Models that can accurately include the large deflections into stability calculations of these aircraft are needed to avoid late stage failures in the development cycle. In order to validate such models, the Pazy wing experiment [1] was conducted as part of the Aeroelastic Prediction Workshop (AePW) Large Deflection Working Group [2][3][4]. This is a simple, yet challenging test case, as the non-linearities have substantial effects on the structural and aeroelastic properties of the wing, with "some trends that are opposite to those obtained in the linear domain" [5].…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Free Wake Panel Method Simulations of a Highly Flexible Wing at Flutter

Ribeiro

Casalino

Ferreira

2022

AIAA AVIATION 2022 Forum

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“…Ignoring the second torsion mode, the results shown in Fig. 9 are very similar to experimental data shown in [4].…”

Section: Flutter Characteristicssupporting

confidence: 85%

Section: Flutter Characteristicssupporting

confidence: 84%

Section: B Aeroelastic Simulations Validationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Free Wake Panel Method Simulations of a Highly Flexible Wing at Flutter

Ribeiro

Casalino

Ferreira

2022

AIAA AVIATION 2022 Forum

View full text Add to dashboard Cite

“…The stability envelope presented in the previous section has supported the planning of wind tunnel experiments to explore the first unstable region (T1-OOP2) without incurring excessive airspeeds or deformations. The full test details and results are presented in [55] and only a representative subset of them are used herein to study the capability of the two numerical methods described here to predict the aeroelastic behavior of very flexible wings. This paper, by presenting the Pazy wing, and initial tests of its structural and aeroelastic behavior, will, hopefully, be the foundation for future works that will study the capabilities of the present and other simulation techniques and the physics of this nonlinear system that is rich in experimental, physical, and simulation challenges.…”

Section: Comparision With Wind Tunnel Datamentioning

confidence: 99%

Flutter Predictions for Very Flexible Wing Wind Tunnel Test

Goizueta¹,

Wynn²,

Palacios³

et al. 2022

Journal of Aircraft

Self Cite

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The stability boundaries of a very flexible wing are sought to inform a wind-tunnel flutter test campaign. The objective is twofold: to identify via simulation the relevant physical processes to be explored while ensuring safe and non-destructive experiments, and to provide a benchmark case for which computational models and test data are freely available. Analyses have been independently carried out using two geometrically nonlinear structural models coupled with potential flow aerodynamics. The models are based on a prototype of the wing for which static load and aeroelastic tests are available, and the experimental results have been successfully reproduced numerically. The wing displays strong geometrically nonlinear effects with static deformations as high as 50% of its span. This results in substantial changes to its structural dynamics, which display several mode crossings that cause the flutter mechanisms to change as a function of deformation. Stability characteristics depend on both the free-stream velocity and the angle of attack. A fast drop of the flutter speed is observed as the wing deforms as the angle of attack is increased, while a large stable region is observed for wing displacements over 25%. The corresponding wind tunnel dynamic tests have validated these predictions.

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Simultaneous measurement of pressure and temperature in a supersonic ejector using FBG sensors

Hegde¹,

Himakar²,

V³

et al. 2022

Meas. Sci. Technol.

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In this work, we have demonstrated the use of Fiber Bragg Grating (FBG) sensors for simultaneous measurement of wall static pressure and temperature in a supersonic ejector. Supersonic ejectors are ground based high speed aerodynamic test facilities characterized by harsh conditions such as high pressure and temperature gradients. FBG based sensor setup was developed consisting of pressure measuring bare FBG and specially designed pressure-insensitive FBG temperature probe that could be mounted on the wall of the supersonic ejector. The FBG temperature probe was used for temperature measurement as well as temperature compensation of pressure measuring FBG sensor. Wall static pressure measurements in the supersonic ejector were carried out at different tank pressures and Mach number flows. The FBG pressure measurements were validated with that of standard piezoresistive based sensor measurements. Both the responses were found to match closely with FBG sensor having a faster response time and higher pressure resolution. Fluid structure interaction simulation was carried out in Comsol Multiphysics to understand the interaction of high speed turbulent flow on the fiber based FBG sensor. The FBG strain profile due to flow-induced stress and its dependence on flow pressure was studied. A detailed analysis of effect of preceding fiber length on FBG pressure measurement was carried out. FBG sensors, owing to their miniature size, ability to withstand harsh environments and multi parameter sensing capability can be used in ground-based aerodynamic test facilities with minimum intrusion to the flow.

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Flutter Tests of the Pazy Wing

Cited by 7 publications

References 4 publications

Free Wake Panel Method Simulations of a Highly Flexible Wing at Flutter

Free Wake Panel Method Simulations of a Highly Flexible Wing at Flutter

Flutter Predictions for Very Flexible Wing Wind Tunnel Test

Simultaneous measurement of pressure and temperature in a supersonic ejector using FBG sensors

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