Airframe/intake–exhaust integration design of flying wing using a multi-bump strategy

2016 ◽  
Vol 231 (13) ◽  
pp. 2396-2407
Author(s):  
Wenbiao Gan ◽  
Zhou Zhou ◽  
Xiaocui Zhang
Keyword(s):  
Present Method ◽  
Simulation Method ◽  
Static Stability ◽  
Aerodynamic Performance ◽  
Transition Model ◽  
Optimization Framework ◽  
Flow Features ◽  
Design Effectiveness ◽  
Drag Ratio ◽  
Longitudinal Static Stability

A multi-bump strategy combines automatic optimization and flow control and is employed in airframe/intake–exhaust integration design of flying wing. The numerical simulation method of [Formula: see text] transition model is verified and used for optimization and validated analysis. According to flow features of basic integration configuration, the multi-bump strategy is proposed. Based on the strategy, the optimization framework is constructed and applied to the design. The research results show that the present method has good design effectiveness. The cruise lift-drag ratio improves 4.1% and longitudinal static stability increases 1.1% at large attack angle. The multi-bump strategy is a skillfully deflected means to improve aerodynamic performance.

scholarly journals Simulation Analysis of the Aerodynamic Performance of a Bionic Aircraft with Foldable Beetle Wings in Gliding Flight

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Caidong Wang ◽  
Yu Ning ◽  
Xinjie Wang ◽  
Junqiu Zhang ◽  
Liangwen Wang
Keyword(s):  
Simulation Analysis ◽  
Simulation Method ◽  
Aerodynamic Characteristics ◽  
Aerodynamic Performance ◽  
Elastic Model ◽  
Flight Performance ◽  
Flexible Wings ◽  
Gliding Flight ◽  
Drag Ratio ◽  
Gliding Movement

Beetles have excellent flight performance. Based on the four-plate mechanism theory, a novel bionic flapping aircraft with foldable beetle wings was designed. It can perform flapping, gliding, wing folding, and abduction/adduction movements with a self-locking function. In order to study the flight characteristics of beetles and improve their gliding performance, this paper used a two-way Fluid-Structure Interaction (FSI) numerical simulation method to focus on the gliding performance of the bionic flapping aircraft. The effects of elastic model, rigid and flexible wing, angle of attack, and velocity on the aerodynamic characteristics of the aircraft in gliding flight are analyzed. It was found that the elastic modulus of the flexible hinges has little effect on the aerodynamic performance of the aircraft. Both the rigid and the flexible wings have a maximum lift-to-drag ratio when the attack angle is 10°. The lift increased with the increase of the gliding speed, and it was found that the lift cannot support the gliding movement at low speeds. In order to achieve gliding, considering the weight and flight performance, the weight of the microair vehicle is controlled at about 3 g, and the gliding speed is guaranteed to be greater than 6.5 m/s. The results of this study are of great significance for the design of bionic flapping aircrafts.

scholarly journals Stability-based motion planning for a modular morphing wing

2021 ◽  
Author(s):  
Michael C. F. Kwong
Keyword(s):  
Selection Process ◽  
Static Stability ◽  
Path Selection ◽  
Critical Parameters ◽  
Morphing Wing ◽  
Wing Geometry ◽  
Variable Geometry Truss ◽  
Different Levels ◽  
Longitudinal Static Stability

Aircraft wing geometry morphing is a technology that has seen recent interest due to demand for aircraft to improve aerodynamic performance for fuel saving. One proposed idea to alter wing geometry is by a modular morphing wing designed through a discretization method and constructed using variable geometry truss mechanisms (VGTM). For each morphing maneuver, there are sixteen possible actuation paths for each VGTM module, and thus offering a three module morphing wing to have a total of 16(to the power of 3) permutations of actuation paths for one morphing maneuver. Focused on longitudinal static stability, critical parameters and aircraft stability theory, this thesis proposes a method to find an optimal actuation path for a designated maneuver iteratively. A case study of a three module morphing wing demonstrated the actuation path selection process. Numerically, different actuation paths had different levels of longitudinal static stability; these paths were drawn in CATIA and were visually verified.

Aerodynamic Performance and Static Stability Characteristics of Aircraft with Tail-Mounted Propellers

2021 ◽  
pp. 1-18
Author(s):  
Nando van Arnhem ◽  
Reynard de Vries ◽  
Tomas Sinnige ◽  
Roelof Vos ◽  
Leo L. M. Veldhuis
Keyword(s):  
Static Stability ◽  
Aerodynamic Performance

The aerodynamic optimisation of a low-Reynolds paper plane with adjoint method

2020 ◽  
pp. 1-15
Author(s):  
Y. Zhang ◽  
X. Zhang ◽  
G. Chen
Keyword(s):  
Adjoint Method ◽  
Low Cost ◽  
Aerodynamic Performance ◽  
Discrete Adjoint ◽  
Design Variables ◽  
Limited Variation ◽  
Aerial Vehicle ◽  
Paper Plane ◽  
Drag Ratio ◽  
Lift To Drag Ratio

ABSTRACT The aerodynamic performance of a deployable and low-cost unmanned aerial vehicle (UAV) is investigated and improved in present work. The parameters of configuration, such as airfoil and winglet, are determined via an optimising process based on a discrete adjoint method. The optimised target is locked on an increasing lift-to-drag ratio with a limited variation of pitching moments. The separation that will lead to a stall is delayed after optimisation. Up to 128 design variables are used by the optimised solver to give enough flexibility of the geometrical transformation. As much as 20% enhancement of lift-to-drag ratio is gained at the cruise angle-of-attack, that is, a significant improvement in the lift-to-drag ratio adhering to the preferred configuration is obtained with increasing lift and decreasing drag coefficients, essentially entailing an improved aerodynamic performance.

Numerical Simulation of Ultrasonic Shear Wave Propagation Based on the Finite Element Method

2014 ◽  
Vol 488-489 ◽  
pp. 926-929 ◽  
Author(s):  
Jian Ma ◽  
Yang Zhao ◽  
Ji Hua Sun ◽  
Shuai Liu
Keyword(s):  
Numerical Simulation ◽  
Shear Wave ◽  
Present Method ◽  
Steel Plate ◽  
Mode Conversion ◽  
Simulation Method ◽  
The Finite Element Method ◽  
Propagation Process ◽  
The Time Domain ◽  
Ultrasonic Shear

The present paper provided a kind of numerical simulation method which was employed to guide the process of ultrasonic nondestructive testing and analyze the inspection results. The simulation concerning the propagation process of shear wave in the steel plate was carried out using the ANSYS, according to the mechanism of ultrasonic mode conversion. Then, the frequency, velocity and refraction angle were extracted from the time-domain date in order to verify the simulation. It is found that the result of simulation agrees well with the theoretical one, which shows that the present method is correct and reliable.

Analysis of Motion in Longitudinal Plane of Negative Buoyancy Vehicle

2012 ◽  
Vol 457-458 ◽  
pp. 1367-1376 ◽  
Author(s):  
Hui Yan ◽  
Tong Ge ◽  
Jian Min Liu
Keyword(s):  
System Theory ◽  
Autonomous Underwater Vehicle ◽  
Underwater Vehicle ◽  
Static Stability ◽  
Constant Load ◽  
Longitudinal Plane ◽  
Metacentric Height ◽  
Negative Buoyancy ◽  
Drag Ratio ◽  
Analysis Of Motion

This article described a novel type of autonomous underwater vehicle and modeled the dynamics. This kind of vehicle looked like an air-plane with large wings and worked under the condition of negative buoyancy. The motions of negative-buoyancy-vehicle (NBV) in the longitudinal plane were analyzed through linear system theory. This paper divided motion of NBV into a few modes in the longitudinal plane and provided a method of reduction of order to simplify the analysis, as well as gave the criterion of static stability under constant load in longitudinal plane. It had been found that the maneuverability and stability of NBV was related to many factors such as the velocity, lift-drag ratio, buoyancy and metacentric height. All of the conclusions could be applied on NBV design.

Longitudinal static stability analysis of hypersonic waveriders

2014 ◽  
Vol 44 (10) ◽  
pp. 1114-1122 ◽  
Author(s):  
KeMu WANG ◽  
ChenAn ZHANG ◽  
FaMin WANG ◽  
ZiAn JIA
Keyword(s):  
Stability Analysis ◽  
Static Stability ◽  
Longitudinal Static Stability
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