Aerodynamic Characteristics Analysis of Refueling Drogue Under the Influence of Bow Wave Effect Based on Patched Grid Technology

2021 ◽  
pp. 803-813
Author(s):  
Wangyi Zhou ◽  
Qian Zhao ◽  
Xiheng Zang ◽  
Qingsong Liu ◽  
Lei Qiao ◽  
...  
Keyword(s):  
Aerodynamic Characteristics ◽  
Grid Technology ◽  
Wave Effect ◽  
Bow Wave ◽  
Characteristics Analysis

Aerodynamic Characteristics Analysis of High-Speed Train on Cutting under Crosswinds

2013 ◽  
Vol 300-301 ◽  
pp. 62-67
Author(s):  
Kun Ye ◽  
Ren Xian Li
Keyword(s):  
High Speed ◽  
Three Dimensional ◽  
Aerodynamic Characteristics ◽  
High Speed Train ◽  
Aerodynamic Forces ◽  
Cutting Depth ◽  
Cutting Slope ◽  
Characteristics Analysis ◽  
Relationship Of ◽  
The Relationship

Cutting is an effective device to reduce crosswind loads acting on trains. The cutting depth, width and gradient of slope are important factors for design and construction of cutting. Based on numerical analysis methods of three-dimensional viscous incompressible aerodynamics equations, aerodynamic side forces and yawing moments acting on the high-speed train, with different depths and widths of cutting，are calculated and analyzed under crosswinds，meanwhile the relationship of the gradient of cutting slope and transverse aerodynamic forces acting on trains are also studied. Simulation results show that aerodynamic side forces and yawing moments acting on the train（the first, middle and rear train）decrease with the increase of cutting depth. The relationship between transverse forces (moments) coefficients acting on the three sections and the cutting depth basically is the three cubed relation. The bigger is cutting width，the worse is running stability of train. The relationship between yawing moments coefficients acting each body of the train and the cutting width approximately is the three cubed relation. The transverse Aerodynamic forces decreased gradually with the increase of the gradient of cutting slope, the relationship between yawing moments coefficients acting each body of the train and the gradient of cutting slope basically is the four cubed relation.

scholarly journals Methodology for calculating the efficiency of the rudders of the tandem aircraft

2021 ◽  
pp. 11-21
Author(s):  
Illya Bilous ◽  
Illya Kryvohatko ◽  
Yurii Yakovlev
Keyword(s):  
Wind Tunnel ◽  
Rapid Development ◽  
Aerodynamic Characteristics ◽  
Wind Tunnel Experiment ◽  
Wind Tunnels ◽  
Analysis Tool ◽  
It Impacts ◽  
Characteristics Analysis ◽  
The Stability

As of recent rapid development in the field of UAVs, unusual aerodynamic practices can be used, for example, the tandem scheme. In early planning stages, it’s important to evaluate aerodynamic characteristics of the chosen scheme and to approximate its balancing losses, as it impacts the stability and controllability of the craft. The most effective way of aerodynamic characteristics analysis is done using wind tunnels. However, it requires considerable investments in both financial terms and time, when designing the model, conducting the experiment and processing the results. Because of that, it’s worthwhile to consider the simple CFD calculations (XFOIL). This paper calculates aerodynamic characteristics of a tandem-scheme based “A-8” aircraft using XFLR5 analysis tool with the results compared to a real wind tunnel experiment. The overall conclusion of the paper is a recommendation to consider XFLR5 for early planning stages for advanced balancing losses calculation approximation.

Design and Aerodynamic Characteristics Analysis of a Section Morphing Wing Based on Smart Materials

2013 ◽  
Vol 753-755 ◽  
pp. 1764-1767
Author(s):  
Yue Min Yu
Keyword(s):  
Mach Number ◽  
Shape Memory ◽  
Smart Materials ◽  
Shape Memory Polymer ◽  
Aerodynamic Characteristics ◽  
Morphing Wing ◽  
Ratio Increase ◽  
Wing Section ◽  
Characteristics Analysis ◽  
Drag Ratio

This paper discusses the design of a section morphing wing that permits a change in the wing section while simultaneously supporting structural wing loads. Section morphing wing allows for two discreet airfoil of the wing. The airfoil 1 is original airfoil maintained by NACA 4412 rib sections. The section morphing wing uses shape memory alloy spring actuator to drive wing section deformation. Skins of the section morphing wing uses shape memory polymer. Computational aerodynamics are used to estimate the performance and dynamic characteristics of each wing section of this section morphing wing as its wing section is changed. Results show that when angle of attach (AOA) is 0 deg, the lift-drag ratio decrease as the airfoil thickness decreases when mach number is less than 0.9 and the lift-drag ratio increase as the airfoil thickness decreases when mach number is greater than 0.9. When AOA is 5deg, the lift-drag ratio increase as the airfoil thickness decreases . The lift-drag ratio decrease as the airfoil thickness decreases when mach number is less than 0.7. When AOA is 10deg, the lift-drag ratio increase as the airfoil thickness decreases when mach number is greater than 0.7. We can chose airfoil 1 or airfoil 2 according to variation flight conditions.

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