scholarly journals Gust Load Alleviation including Geometric Nonlinearities Based on Dynamic Linearization of Structural ROM

2019 ◽  
Vol 2019 ◽  
pp. 1-20
Author(s):  
Chao An ◽  
Chao Yang ◽  
Changchuan Xie ◽  
Yang Meng
Keyword(s):  
Wind Tunnel ◽  
Wind Tunnel Test ◽  
Kernel Functions ◽  
Structural Deformation ◽  
Control Technique ◽  
Feedback Signal ◽  
Response Analysis ◽  
Geometric Nonlinearities ◽  
Gust Load Alleviation ◽  
Gust Response

This paper describes a framework for an active control technique applied to gust load alleviation (GLA) of a flexible wing, including geometric nonlinearities. Nonlinear structure reduced order model (ROM) and nonplanar double-lattice method (DLM) are used for structural and aerodynamic modeling. The structural modeling method presented herein describes stiffness nonlinearities in polynomial formulation. Nonlinear stiffness can be derived by stepwise regression. Inertia terms are constant with linear approximation. Boundary conditions and kernel functions in the nonplanar DLM are determined by structural deformation to reflect a nonlinear effect. However, the governing equation is still linear. A state-space equation is established in a dynamic linearized system around the prescribed static equilibrium state after nonlinear static aeroelastic analysis. Gust response analysis can be conducted subsequently. For GLA analysis, a classic proportional-integral-derivative (PID) controller treats a servo as an actuator and acceleration as the feedback signal. Moreover, a wind tunnel test has been completed and the effectiveness of the control technology is validated. A remote-controlled (RC) model servo is chosen in the wind tunnel test. Numerical simulation results of gust response analysis reach agreement with test results. Furthermore, the control system gives GLA efficacy of vertical acceleration and root bending moment with the reduction rate being over 20%. The method described in this paper is suitable for gust response analysis and control strategy design for large flexible wings.

scholarly journals Gust response analysis and wind tunnel test for a high-aspect ratio wing

2016 ◽  
Vol 29 (1) ◽  
pp. 91-103 ◽  
Author(s):  
Yi Liu ◽  
Changchuan Xie ◽  
Chao Yang ◽  
Jialin Cheng
Keyword(s):  
Wind Tunnel ◽  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Wind Tunnel Test ◽  
Response Analysis ◽  
Gust Response

scholarly journals Evaluation of Wind-Induced Response Bounds of High-Rise Buildings Based on a Nonrandom Interval Analysis Method

2018 ◽  
Vol 2018 ◽  
pp. 1-14
Author(s):  
Xianglei Wei ◽  
An Xu ◽  
Ruohong Zhao
Keyword(s):  
Wind Speed ◽  
Wind Tunnel ◽  
Wind Tunnel Test ◽  
Wind Load ◽  
Upper And Lower Bounds ◽  
Induced Response ◽  
Response Analysis ◽  
Analysis Method ◽  
High Rise ◽  
Interval Analysis Method

The traditional wind-induced response analysis of high-rise buildings conventionally considers the wind load as a stationary stochastic process. That is, for a certain wind direction angle, the reference wind speed (usually refers to the mean wind speed at the building height) is assumed to be a constant corresponding to a certain return period. Combined with the recorded data in wind tunnel test, the structural response can be computed using the random vibration theory. However, in the actual typhoon process, the average wind speed is usually time-variant. This paper combines the interval process model and the nonrandom vibration analysis method with the wind tunnel test and proposes a method for estimating the response boundary of the high-rise buildings under nonstationary wind loads. With the given upper and lower bounds of time-variant wind excitation, this method can provide an effective calculation tool for estimating wind-induced vibration bounds for high-rise buildings under nonstationary wind load. The Guangzhou East tower, which is 530 m high and the highest supertall building in Guangzhou, China, was taken as an example to show the effectiveness of the method. The obtained boundary response can help disaster prevention and control during the passage of typhoons.

The Stability Analysis of the Driving Rod of the Wind Tunnel Test Model Based on Workbench

2015 ◽  
Vol 799-800 ◽  
pp. 538-542
Author(s):  
Zi Yan Shao ◽  
Wen Jia Chen ◽  
Yong Jin Hu ◽  
Guan Jian Li
Keyword(s):  
Wind Tunnel ◽  
Degrees Of Freedom ◽  
Wind Tunnel Test ◽  
Future Research ◽  
Response Analysis ◽  
Test Model ◽  
Main Research ◽  
Theoretical Support ◽  
Harmonic Response Analysis ◽  
The Stability

The ANSYS Workbench is used in this paper to analyse a kind of wind tunnel test model support platform with 5 degrees of freedom. The driving rod of the pitch motion is chosen as the main research project. By using static structural analysis, modal analysis and harmonic response analysis, a detailed analysis is made on the stress, deformation and frequency of the driving rod, and provides theoretical support for the future research on the stability of the institution.

scholarly journals Design and Optimization of an Aeroservoelastic Wind Tunnel Model

Fluids ◽  
2020 ◽  
Vol 5 (1) ◽  
pp. 35 ◽  
Author(s):  
Johannes K. S. Dillinger ◽  
Yasser M. Meddaikar ◽  
Jannis Lübker ◽  
Manuel Pusch ◽  
Thiemo Kier
Keyword(s):  
Finite Element ◽  
Wind Tunnel ◽  
Wind Tunnel Test ◽  
Objective Functions ◽  
Dynamic Identification ◽  
Wind Tunnel Model ◽  
Design And Optimization ◽  
Aeroelastic Model ◽  
Tunnel Model ◽  
Gust Load Alleviation

Through the combination of passive and active load alleviation techniques, this paper presents the design, optimization, manufacturing, and update of a flexible composite wind tunnel model. In a first step, starting from the specification of an adequate wing and trailing edge flap geometry, passive, static aeroelastic stiffness optimizations for various objective functions have been performed. The second optimization step comprised a discretization of the continuous stiffness distributions, resulting in manufacturable stacking sequences. In order to determine which of the objective functions investigated in the passive structural optimization most efficiently complemented the projected active control schemes, the condensed modal finite element models were integrated in an aeroelastic model, involving a dedicated gust load alleviation controller. The most promising design was selected for manufacturing. The finite element representation could be updated to conform to the measured eigenfrequencies, based on the dynamic identification of the model. Eventually, a wind tunnel test campaign was conducted in November 2018 and results have been examined in separate reports.

scholarly journals GPC-Based Gust Response Alleviation for Aircraft Model Adapting to Various Flow Velocities in the Wind Tunnel

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Yuting Dai ◽  
Chao Yang
Keyword(s):  
Wind Tunnel ◽  
Wind Tunnel Test ◽  
Open Loop ◽  
Ar Model ◽  
Aircraft Model ◽  
Input Amplitude ◽  
Aeroelastic Model ◽  
Wing Tip ◽  
Gust Response ◽  
Flow Velocities

A unified autoregressive (AR) model is identified, based on the wind tunnel test data of open-loop gust response for an aircraft model. The identified AR model can be adapted to various flow velocities in the wind tunnel test. Due to the lack of discrete gust input measurement, a second-order polynomial function is used to approximate the gust input amplitude by flow velocity. Afterwards, with the identified online aeroelastic model, the modified generalized predictive control (GPC) theory is applied to alleviate wing tip acceleration induced by sinusoidal gust. Finally, the alleviation effects of gust response at different flow velocities are estimated based on the comparison of simulated closed-loop acceleration with experimental open-loop one. The comparison indicates that, after gust response alleviation, the wing tip acceleration can be reduced up to 20% at the tested velocities ranging from 12 m/s to 24 m/s. Demonstratively, the unified control law can be adapted to varying wind tunnel velocities and gust frequencies. It does not need to be altered at different test conditions, which will save the idle time.

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