scholarly journals Effect of a Slat Arm Door on the Wing Efficiency of a Commercial Aircraft.

2021 ◽  
Author(s):  
Sharman Perera
Keyword(s):  
Residence Time ◽  
Coming Out ◽  
Cfd Simulation ◽  
Leading Edge ◽  
Aerodynamic Performance ◽  
Cfd Analysis ◽  
Inert Particle ◽  
Commercial Aircraft ◽  
Local Flow ◽  
Closed Model

The objective of this thesis is to determine the influence of a slat arm door on the aerodynamic performance of a wing of a commercial aircraft during it's take off and landing configurations using CFD simulation. The slats are extended forward by extendable arms coming out from the leading edge of the wing after the slat arm is deployed. CFD analysis of wing and slat configuration of the aircraft showed that the removal of this slat door at higher angle of attacks increased the drag by 0.88%, reduced the lift by 1.29%, increased the inert particle residence time inside the slat door compartment by 200.00% and increased the local flow separation area on the top surface of the wing by 42.81% with reference to the closed model.

scholarly journals Effect of a Slat Arm Door on the Wing Efficiency of a Commercial Aircraft.

2021 ◽  
Author(s):  
Sharman Perera
Keyword(s):  
Residence Time ◽  
Coming Out ◽  
Cfd Simulation ◽  
Leading Edge ◽  
Aerodynamic Performance ◽  
Cfd Analysis ◽  
Inert Particle ◽  
Commercial Aircraft ◽  
Local Flow ◽  
Closed Model

The objective of this thesis is to determine the influence of a slat arm door on the aerodynamic performance of a wing of a commercial aircraft during it's take off and landing configurations using CFD simulation. The slats are extended forward by extendable arms coming out from the leading edge of the wing after the slat arm is deployed. CFD analysis of wing and slat configuration of the aircraft showed that the removal of this slat door at higher angle of attacks increased the drag by 0.88%, reduced the lift by 1.29%, increased the inert particle residence time inside the slat door compartment by 200.00% and increased the local flow separation area on the top surface of the wing by 42.81% with reference to the closed model.

scholarly journals Optimization for Cavitation Inception Performance of Pump-Turbine in Pump Mode Based on Genetic Algorithm

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Ran Tao ◽  
Ruofu Xiao ◽  
Wei Yang ◽  
Fujun Wang ◽  
Weichao Liu
Keyword(s):  
Genetic Algorithm ◽  
Pressure Drop ◽  
Cfd Simulation ◽  
Pressure Coefficient ◽  
Leading Edge ◽  
Algorithm Optimization ◽  
Pump Mode ◽  
Local Flow ◽  
Cavitation Inception ◽  
Blade Thickness

Cavitation is a negative factor of hydraulic machinery because of its undesirable effects on the operation stability and safety. For reversible pump-turbines, the improvement of cavitation inception performance in pump mode is very important due to the strict requirements. The geometry of blade leading edge is crucial for the local flow separation which affects the scale and position of pressure drop. Hence, the optimization of leading edge shape is helpful for the improvement of cavitation inception performance. Based on the genetic algorithm, optimization under multiple flow rate conditions was conducted by modifying the leading edge ellipse ratio and blade thickness on the front 20% meanline. By using CFD simulation, optimization was completed with obvious improvements on the cavitation inception performance. CFD results show that the pressure drop location had moved downstream with the increasement of the minimum pressure coefficient. Experimental verifications also got an obvious enhancement of cavitation inception performance. The stability and safety was improved by moving the cavitation inception curve out of the operating range. This optimization is proved applicable and effective for the engineering applications of reversible pump-turbines.

scholarly journals Effect of Chordwise Struts and Misaligned Flow on the Aerodynamic Performance of a Leading-Edge Inflatable Wing

2021 ◽  
Author(s):  
Axelle Viré ◽  
Geert Lebesque ◽  
Mikko Folkersma ◽  
Roland Schmehl
Keyword(s):  
Separation Bubble ◽  
Flow Characteristics ◽  
Leading Edge ◽  
Suction Side ◽  
Aerodynamic Performance ◽  
Navier Stokes ◽  
Local Flow ◽  
Energy Applications ◽  
Flow Configurations ◽  
Lift And Drag

Steady-state Reynolds-Averaged Navier-Stokes (RANS) simulations are performed for a leading-edge inflatable wing for airborne wind energy applications. Expanding on previous work where only the inflatable leading edge tube was considered, eight additional inflatable strut tubes that support the wing canopy are now included. The shape of the wing is considered to be constant. The influence of the strut tubes on the aerodynamic performance of the wing and the local flow field is assessed, considering flow configurations with and without side-slip. The simulations show that the aerodynamic performance of the wing decreases with increasing side-slip component of the inflow. On the other hand, the chordwise struts have little influence on the integral lift and drag of the wing, irrespective of the side-slip component. The overall flow characteristics are in good agreement with previous studies. In particular, it is confirmed that at a low Reynolds number of Re=10^5, a laminar separation bubble exists on the suction side of this hypothetical rigid wing shape with perfectly smooth surface. The destruction of this bubble at low angles of attack impacts negatively on the aerodynamic performance.

Experimental and Numerical Research of Fan Bypass Duct Flows in Japanese Environmentally Compatible Engine for Small Aircraft Project

2011 ◽  
Author(s):  
Yoshinori Ooba ◽  
Takeshi Murooka ◽  
Takashi Yamane ◽  
Osamu Nozaki ◽  
Takeshi Ishiyama
Keyword(s):  
Cfd Simulation ◽  
Aerodynamic Performance ◽  
Measured Data ◽  
Turbine Engines ◽  
Cfd Analysis ◽  
Gas Turbine Engines ◽  
Aircraft Engines ◽  
Numerical Research ◽  
Long Nose ◽  
Small Aircraft

This research aims at developing fan integration technologies to improve the installation loss due to the fan/OGV/strut/pylon interaction of gas-turbine engines for small aircraft on Small Aircraft Project in Japan (the ECO Engine Project). Researches on experimental measurement using fan rig testing and numerical prediction using unsteady CFD analysis are conducted. The UPACS code which is developed by JAXA is used in order to accurately simulate the phenomena which occur in the interaction between a rotating fan and its downstream obstacles like strut/pylon in the fan duct. The accuracy of the CFD simulation is also validated by the measured data acquired in the rig testing. Through the investigations, its interaction mechanisms are clarified and the reducing technologies of such interaction for small aircraft engines are created. In the paper, the achievement of the improved aerodynamic performance by introducing the new concept of the long nose shaped fat pylon L/E are demonstrated.

scholarly journals Towards higher aerodynamic efficiency of propeller-driven aircraft with distributed propulsion

2021 ◽  
Author(s):  
Dennis Keller
Keyword(s):  
Performance Indicator ◽  
Leading Edge ◽  
Substantial Improvement ◽  
Initial Assessment ◽  
Local Flow ◽  
Propulsive Efficiency ◽  
Thrust Distribution ◽  
Distributed Propulsion ◽  
Wing Tip ◽  
Cruise Flight

AbstractThe scope of the present paper is to assess the potential of distributed propulsion for a regional aircraft regarding aero-propulsive efficiency. Several sensitivities such as the effect of wingtip propellers, thrust distribution, and shape modifications are investigated based on a configuration with 12 propulsors. Furthermore, an initial assessment of the high-lift performance is undertaken in order to estimate potential wing sizing effects. The performance of the main wing and the propellers are thereby equally considered with the required power being the overall performance indicator. The results indicate that distributed propulsion is not necessarily beneficial regarding the aero-propulsive efficiency in cruise flight. However, the use of wing tip propellers, optimization of the thrust distribution, and wing resizing effects lead to a reduction in required propulsive power by $$-2.9$$ - 2.9 to $$-3.3\,\%$$ - 3.3 % compared to a configuration with two propulsors. Adapting the leading edge to the local flow conditions did not show any substantial improvement in cruise configuration to date.

Aerodynamic performance effects due to small leading-edge ice (roughness) on wings and tails

1993 ◽  
Vol 30 (6) ◽  
pp. 807-812 ◽  
Author(s):  
Walter O. Valarezo ◽  
Frank T. Lynch ◽  
Robert J. McGhee
Keyword(s):  
Leading Edge ◽  
Aerodynamic Performance ◽  
Ice Roughness ◽  
Performance Effects

scholarly journals Numerical simulation of flapping airfoil with alula

2020 ◽  
Vol 12 ◽  
pp. 175682932097798
Author(s):  
Han Bao ◽  
Wenqing Yang ◽  
Dongfu Ma ◽  
Wenping Song ◽  
Bifeng Song
Keyword(s):  
Aerodynamic Force ◽  
Angle Of Attack ◽  
Leading Edge ◽  
Aerodynamic Performance ◽  
Geometric Parameters ◽  
Flight Performance ◽  
Relative Angle ◽  
Vertical Distance ◽  
Unsteady Effect ◽  
Flapping Airfoil

Bionic micro aerial vehicles have become popular because of their high thrust efficiency and deceptive appearances. Leading edge or trailing edge devices (such as slots or flaps) are often used to improve the flight performance. Birds in nature also have leading-edge devices, known as the alula that can improve their flight performance at large angles of attack. In the present study, the aerodynamic performance of a flapping airfoil with alula is numerically simulated to illustrate the effects of different alula geometric parameters. Different alula relative angles of attack β (the angle between the chord line of the alula and that of the main airfoil) and vertical distances h between the alula and the main airfoil are simulated at pre-stall and post-stall conditions. Results show that at pre-stall condition, the lift increases with the relative angle of attack and the vertical distance, but the aerodynamic performance is degraded in the presence of alula compared with no alula, whereas at post-stall condition, the alula greatly enhances the lift. However, there seems to be an optimal relative angle of attack for the maximum lift enhancement at a fixed vertical distance considering the unsteady effect, which may indicate birds can adjust the alula twisting at different spanwise positions to achieve the best flight performance. Different alula geometric parameters may affect the aerodynamic force by modifying the pressure distribution along the airfoil. The results are instructive for design of flapping-wing bionic unmanned air vehicles.

Aerodynamic Analysis of an Airfoil With Leading Edge Pitting Erosion

2017 ◽  
Vol 139 (6) ◽  
Author(s):  
Yan Wang ◽  
Ruifeng Hu ◽  
Xiaojing Zheng
Keyword(s):  
Wind Turbine ◽  
Indirect Effects ◽  
Leading Edge ◽  
Aerodynamic Performance ◽  
Navier Stokes ◽  
Distribution Area ◽  
Navier Stokes Equation ◽  
Turbine Performance ◽  
Wind Turbine Airfoil ◽  
Cfd Method

Leading edge erosion is a considerable threat to wind turbine performance and blade maintenance, and it is very imperative to accurately predict the influence of various degrees of erosion on wind turbine performance. In the present study, an attempt to investigate the effects of leading edge erosion on the aerodynamics of wind turbine airfoil is undertaken by using computational fluid dynamics (CFD) method. A new pitting erosion model is proposed and semicircle cavities were used to represent the erosion pits in the simulation. Two-dimensional incompressible Reynolds-averaged Navier–Stokes equation and shear stress transport (SST) k–ω turbulence model are adopted to compute the aerodynamics of a S809 airfoil with leading edge pitting erosions, where the influences of pits depth, densities, distribution area, and locations are considered. The results indicate that pitting erosion has remarkably undesirable influences on the aerodynamic performance of the airfoil, and the critical pits depth, density, and distribution area degrade the airfoil aerodynamic performance mostly were obtained. In addition, the dominant parameters are determined by the correlation coefficient path analysis method, results showed that all parameters have non-negligible effects on the aerodynamics of S809 airfoil, and the Reynolds number is of the most important, followed by pits density, pits depth, and pits distribution area. Meanwhile, the direct and indirect effects of these factors are analyzed, and it is found that the indirect effects are very small and the parameters can be considered to be independent with each other.

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