Jun Liu

Dr. Jun Liu


Research Focus & Metrics

Academic Career Length

5Years (2022-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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3 December 2022 in Aerospace
Verified
Journal Article
Open access
PDF file
JLJun Liu
Jun Liu
WQWei Qian
Wei Qian
Yuguang BaiYuguang Bai
Yuguang Bai
XXXu Xu
Xu Xu
The V-tail configuration has excellent stealth performance and has been using widely in the aerodynamic shape design of advanced aircraft. Many recent studies have focused on numerical simulation about V-tail configuration flight performance. The relative wind tunnel tests still need to be developed. This challenge is a focused aspect in such research. In the present experimental study, the role of flight control law was investigated in order to keep the test model in the target attitude and height. An effective design method of a full model of the aircraft with twin V-tails is proposed based on CFD evaluation. This model was manufactured based on the design of a two degrees of freedom support system via a Chinese wind tunnel. A longitudinal flight control law was proposed and simulated. Wind tunnel tests were employed to find the effectiveness of the model design and the control law. It is seen from the results that the proposed experimental method via a full model of the aircraft with twin V-tails and a novel longitudinal flight control law is effective. These test results can provide appliable contributions on the development of the support system for wind tunnel experiments. The proposed model design and test methods can be useful for applications in the aeroelastic wind tunnel tests of the full model aircrafts.

10 December 2024 in Aerospace
Verified
Journal Article
Open access
PDF file
XLXing Li
Xing Li
WQWei Qian
Wei Qian
XHXin Hu
Xin Hu
XAXinyu Ai
Xinyu Ai
JLJun Liu
Jun Liu
Large transport aircraft tend to adopt a wing layout with a high aspect ratio and swept-back angle due to the requirement of a high lift-to-drag ratio. Composite material is typically employed to ensure the light weight of the structure, causing serious static aeroelasticity problems to the aircraft. When the airplane is flying in the transonic region, its aerodynamic load is very complex, and the large load leads to large deformation of the wing, triggering geometric nonlinear effects, which further affects the static aerodynamic elasticity characteristics of the wing. In this study, in order to study the static aeroelastic characteristics of the transonic flow of a high-aspect-ratio airfoil, a new design method of the scaled similar optimization model is described, and the change in the model lift coefficient due to geometrically nonlinear static aeroelasticity effects when the angle of attack is changed was investigated by using simulation and wind tunnel test methods. In order to ensure the accuracy of the wing shape when the model was deformed greatly, this study employed the structural design scheme of the wing with the skin as the main stiffness component, and the thicknesses of different regions of the skin were used as the design variables for the stiffness optimization design. The engineering algorithm of nonlinear finite elements was used in this study to calculate the curve of lift with the angle of attack considering the geometric nonlinear static aeroelasticity effect. The results show that the similarity optimization process employed in this study can be used to complete the design of the high-speed aerostatic wing test model, and the wind tunnel test results show that geometric nonlinearity has a large impact on the lift coefficient of the wing.