With the increasing use of composite materials in aviation, structural aircraft design often becomes limited by stiffness, rather than strength. As a consequence, aeroelastic analysis becomes more important to optimize both aircraft structures and control algorithms. A low computational cost aeroelasticity model based on VLM and rigid-body dynamics is proposed in this work. UAV flight testing is performed to evaluate the accuracy of the proposed model. Two flight sections are chosen to be modeled based on recorded aerodynamic surface control data. The calculated accelerations are compared with recorded flight data. It is found that the proposed model adequately captures the general flight profile, with acceleration peak errors between −6.2% and +8.4%. The average relative error during the entire flight section is 39% to 44%, mainly caused by rebounds during the beginning and end of pull-up maneuvers. The model could provide useful results for the initial phases of aircraft control law design when comparing different control algorithms.

The use of vibrational transport for granular materials has significantly increased in the technological industry due to its reliability, operational efficiency, cost-effectiveness, and relatively uncomplicated technological setup. These transportation methods typically utilize various forms of asymmetry, such as kinematic, temporal (time), wave, and power asymmetry, to induce controlled motion on oscillating surfaces. This study analyses the motion of the granular materials on an inclined plane, where the central innovation lies in the creation of an additional system asymmetry of frictional conditions that enables the granular materials to move upward. This asymmetry is created by introducing dry friction dynamic manipulations. A mathematical model has been developed to describe the motion of particles under these conditions. The modelling results proved that in an inclined transportation system, the asymmetry of frictional conditions during the oscillation cycle—created through dynamic dry friction manipulations—generates a net frictional force exceeding the gravitational force, thereby enabling the upward movement of granular particles. Additionally, the findings highlighted the key control parameters governing the motion of granular particles. λ, which represents the segment of the sinusoidal period over which the friction is dynamically louvered, serves as a parameter that controls the velocity of a moving particle on an inclined surface. The phase shift ϕ serves as a parameter that controls the direction of the particle’s motion at various inclination angles. Experimental investigations were conducted to assess the practicality of this method. The experimental results confirmed that the granular particles can be transported upward along the inclined surface with an inclination angle of up to 6 degrees, as well as provided both qualitative and quantitative validation of the model by illustrating that motion parameters exhibit comparable responses to the control parameters, and strongly agree with the theoretical findings. The primary advantage of the proposed vibrational transport method is the capacity for precise control of both the direction and velocity of granular particle transport using relatively simple mechanical setups. This method offers mechanical simplicity, low cost, and high reliability. It is well-suited to assembly line and manufacturing environments, as well as to industries involved in the processing and handling of granular materials, where controlled transport, repositioning, or recirculation of granular materials or small discrete components is required.

This paper presents an analysis of how sensitive non-linear vortex lattice method based aeroelasticity models are to variations in viscous airfoil data. These models are a useful low-fidelity tool for fast aeroelastic analysis, often used in early aeroelastic aircraft design and flight control law development. However, they are reliant on pre-existing availability of viscous airfoil data, which can be difficult to obtain without expensive wind tunnel testing or high-fidelity CFD computations. To determine how sensitive the aeroelastic results are to the variations in this airfoil data, a flutter simulation is run for the same wing test case, but using several different airfoil performance curves. The results are analysed to determine how much influence on the final flutter results these changes have.

Panel-based aeroelasticity models are commonly used to conduct mid-fidelity aeroelastic analysis. The unsteady vortex lattice method (UVLM) in particular is used when non-linear aerodynamic corrections are needed, for example by utilizing the $\alpha$-convergence method. While this method is well tested for non-linear corrections in high-Reynolds transonic flows for both steady and unsteady cases, its effectiveness has not been well researched in unsteady low-Reynolds flows. This paper tests the effectiveness of the $\alpha$-convergence method in this regime by comparing modeling results with original wind tunnel test results. In the steady aeroelastic displacement tests, the aerodynamic non-linearity improved the modeling results significantly, with an error under $\pm 10\%$ at all tested angles of attack, compared to a maximum error of $-30.8\%$ for the aerodynamically linear models. In the flutter test case, the aerodynamic non-linearity had less of an impact, with structural non-linearity being more important in this case. However, the maximum flutter speed error for the aerodynamically non-linear model was still lower, at $-14.4\%$, compared to $+19.6\%$ for the aerodynamically linear model.