A generalised force equivalence-based modelling method for a dry wind-tunnel flutter test system

Abstract

Dry wind-tunnel (DWT) flutter test systems model the unsteady distributed aerodynamic force using various electromagnetic exciters. They can be used to test the aeroelastic and aeroservoelastic stability of smart aircraft or high-speed flight vehicles. A new parameterised modelling method at the full system level based on the generalised force equivalence for DWT flutter systems is proposed herein. The full system model includes the structural dynamic model, electromechanical coupling model and fast aerodynamic computation model. An optimisation search method is applied to determine the best locations for measurement and excitation by introducing Fisher’s information matrix. The feasibility and accuracy of the proposed system-level numerical DWT modelling method have been validated for a plate aeroelastic model with four exciters/transducers. The effects of key parameters including the number of exciters, the control time delay, the noise interference and the electrical parameters of the electromagnetic exciter model have also been investigated. The numerical and experimental results indicate that the proposed modelling method achieves good accuracy (with deviations of less than 1.5% from simulations and 4.5% from experimental test results for the flutter speed) and robust performance even in uncertain environments with a 10% noise level.

Real-Time Ground Aeroservoelastic Test for Slender Vehicles Based on Condensed Aerodynamic Force Loading

“…Additionally, in other frequency ranges, both the amplitude and phase errors are extremely small. The force control results align with the conclusions of other researchers [18][19][20][21][22]; the closer to the elastic mode frequencies, the greater the force control error. To validate the control effectiveness of the designed partially decoupled force controller, a linear sweep signal of expected force ( e f ) was simultaneously applied to all four excitation points.…”

“…Subsequently, these condensed forces are transformed into a time-domain state-space model via rational approximation, facilitating their use in real-time ground experiments. In recent years, extensive research has been conducted on the real-time calculation of condensed aerodynamic forces in the GFT [13,[18][19][20][21][22], and these methods are also applicable to the GAT. Therefore, the theoretical details of these methods are not reiterated in this paper.…”

“…Over the subsequent years, notable advancements have been made by researchers. Wu et al [18,19], Wang et al [20], Zhang et al [21], and Yun et al [22] have significantly contributed to refining the method, focusing on aspects such as the condensation of aerodynamic forces and the design of force controllers. Collectively, these efforts have played a crucial role in advancing the effectiveness and precision of the GFT.…”

An Innovative Method for Wind Load Estimation in High-Rise Buildings Based on Green’s Function

“…Furthermore, the use of wind tunnel testing has evolved from simple force measurements to sophisticated aeroelastic testing that can simulate real-world conditions more accurately [6]. This method, despite its higher cost and complexity, provides crucial validation for computational models, ensuring that both theoretical and empirical approaches align with real-world behaviors [7]. As a result, the investigation of wind loads on high-rise buildings, contingent upon the building structure's shape, often necessitates intricate theoretical derivations [8], time-intensive numerical simulations, costly wind tunnel testing, and field measurements.…”

Flutter Boundary Prediction Based on Structural Frequency Response Functions Acquired from Ground Test

“…The orders of these force controllers are lower than H ∞ control, but it is still difficult to extend them to complex models with more EPs. Hu et al [11], Wang and Fan [12], and Zhang et al [13] have made contributions to the GFST method in terms of condensation of aerodynamic forces, force controller design, and test error interference. For force loading, instead of an electromagnetic exciter, Yun and Ham [14,15] used a direct drive linear actuation (DDLA) motor controlled by a simple inverse dynamic method.…”