Flight dynamics modeling and stability analysis of a tube-launched tandem wing aerial vehicle during the deploying process

Abstract

During the subsequent deploying process after the launch, the vehicle experiences dramatic changes in geometry as well as aerodynamics, which cannot be ignored for the flight stability of the aircraft. The investigation on the flight dynamics modeling and stability analysis during the unsteady deploying process is of great significance for the flight control system design and the launch system design. The nonlinear multibody dynamic model of the vehicle, which mainly consists of the airframe and four wings, is established through the Newton–Euler method. Meanwhile, the unsteady vortex lattice method (VLM), which is suitable for tandem wing aircraft and combined with the viscosity effect in light of the strip theory, is proposed to calculate the aerodynamic loads of the vehicle during the deploying process. A series of simulations about the motion of the vehicle after the launch are calculated to analyze the effects of various parameters, including the deploying forms, the start-up time of the power system along with the launching parameters, on the stability of the aerial vehicle in the deployment process. As results indicated, a small difference in the deploying rates of wings and larger deploying rates of wings on the same side are beneficial to the stability of the vehicle during the deploying process. Additionally, it is advantageous to the pitching stability but not the lateral stability of the vehicle when the power system is started earlier. Besides, the attitude control strategy of the vehicle can be formulated in advance by analyzing the attitude of the vehicle with different launch parameters at the launching moment.

An Adaptive Sequential Sampling Strategy-Based Multi-Objective Optimization of Aerodynamic Configuration for a Tandem-Wing UAV via a Surrogate Model

“…Xie data from the wind tunnel tests [37]. Our previous comparative work, which used CFD method, adequately validated the accuracy and capability of non-linear VLM when calculating aerodynamic characteristics for tandem-wing aircraft [11], [12]. The results are shown in Fig.…”

“…The results of these experiments confirmed the capacity of the total drag reduction and the lift increase by arranging the position between the fore and rear wings [8]. By contrast, numerical calculations of aerodynamics investigating tandem-wing configurations have also been carried out in the early stage of aircraft design, which has a financial and time cost advantage, although it offers slight loss of accuracy [9]- [11]. Cheng et al investigated the unsteady aerodynamics in the morphing stage of a tandem-wing UAV by using the improved vortex lattice method.…”

Analysis of longitudinal dynamic stability of tandem wing aircraft

“…The problem of a vertical position of the bi-plane wings and its impact on the dynamic stability was investigated in Goraj et al (1998). The results of aircraft dynamic modelling for a single aircraft configuration but different flight conditions are shown in Cheng et al (2021).…”

A strategy of the longitudinal control for the tandem wing configuration design

“…Both wings are responsible for lift generation, and both wings may play the role of the empennage (both wings may be equipped with the flaps that can be used as a control surfaces). The main feature of the tandem wing configuration is a reduction of the induced drag (Stinton, 2001) caused by the mutual impacts of both wings (Chou et al , 2013; Cheng et al , 2021). According to Munk’s span factor, the lowest induced drag is going to be achieved for two wings placed on the same level and the wing’s stagger (gap-to-chord ratio) equal to 1 (Munk, 1922) .…”