Aerodynamic Performance Analysis of Bodies with Different Cross-Sections

In this research, the flow physics and aerodynamic performance of dragonfly cross sections, used in Micro Aerial Vehicles (MAVs), in low Reynolds are investigated. The main objective of the research is to study the performance of dragonfly wing cross-sections flapping motion in Reynolds 5000 and 10,000. Pitching motion is one of the most important mechanisms in force lifting generation, and the effects of Reynolds number and mean angle of attack on aerodynamic coefficients have been extensively investigated for the pitching motion. In the present study, the geometry of two cross sections of dragonfly was extracted. Incompressible, two-dimensional and unsteady Navier–Stokes equations have been used to simulate the flow. k − ɛ RNG model was used for turbulence modeling. To simulate the wing pitching motion, the dynamic mesh method was used. The results showed that in flapping motion, pitching-up rotation has caused a rapid increase in lift coefficient. Furthermore, it was found that the absence of stall does not increase the lift and drag coefficients, while formation of new strong vorticity layers have caused an increase in lift coefficient. On the other hand, corrugations on the cross sections of the dragonfly in the pitching motion cause the delay of separation and increasing the lift coefficient. In flapping motion and the pitching motion, the lift coefficients of three cross sections were increased due to stronger vorticity layers by reducing the Reynolds number. Due to the existence of corrugations, the first and the second cross sections have good aerodynamic performance, compared to the flat plate. The comparison carried out in the current research showed that the second cross section is a proper replacement for the flat plate in MAVs.

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Aerodynamic performance analysis of an airborne wind turbine system with NREL Phase IV rotor

Energy Conversion and Management ◽

10.1016/j.enconman.2016.12.021 ◽

2017 ◽

Vol 134 ◽

pp. 278-289 ◽

Cited By ~ 17

Author(s):

Muhammad Saeed ◽

Man-Hoe Kim

Keyword(s):

Performance Analysis ◽

Wind Turbine ◽

Aerodynamic Performance ◽

Wind Turbine System ◽

Phase Iv

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Unsteady aerodynamic performance analysis of an airborne wind turbine under load varying conditions at high altitude

Energy Conversion and Management ◽

10.1016/j.enconman.2020.112696 ◽

2020 ◽

Vol 210 ◽

pp. 112696 ◽

Cited By ~ 1

Author(s):

Qazi Shahzad Ali ◽

Man-Hoe Kim

Keyword(s):

Performance Analysis ◽

Wind Turbine ◽

High Altitude ◽

Aerodynamic Performance ◽

Unsteady Aerodynamic

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Aerodynamic performance of aerofoils obtained from a geometric offset applied to a given initial aerofoil

Open Engineering ◽

10.1515/eng-2016-0098 ◽

2016 ◽

Vol 6 (1) ◽

Cited By ~ 1

Author(s):

Diogo Sousa ◽

Pedro Gamboa ◽

David Melo

Keyword(s):

Energy Efficiency ◽

Cross Sections ◽

Aerodynamic Characteristics ◽

Aerodynamic Performance ◽

Specific Design ◽

Morphing Aircraft ◽

Wing Span ◽

Structural Support ◽

Drag And Lift ◽

Geometric Changes

Abstract Many studies concerning morphing aircraft concepts in which enhanced performance and increased energy efficiency are two of the main goals have been recently conducted. Some of those concepts deal with wing span changes. In line with those, in a variable-span wing of the telescopic type, the cross-sections of the sliding panels, whether be two, three or more, must be made geometrically compatible among them. This requirement serves two purposes: to minimize the aerofoils’ geometric discontinuity which negatively affects wing drag and lift; and to provide a simple structural support between any two sliding panels. This paper describes the methodology employed to develop geometrically compatible aerofoils obtained from a constant geometric offset applied to a given initial aerofoil. This methodology is used to create inward offset aerofoils and outward offset aerofoils. The geometric and aerodynamic characteristics of the resulting offset aerofoils are compared with those of the original aerofoils. From the analysis of six different original aerofoils, strong trends in the geometric changes and in the aerodynamic characteristics of the resulting inward and outward offset aerofoils are observed. Ultimately, this study can help a telescopic wing designer decide whether an inward or an outward offset aerofoil is more appropriate for the specific design at hand.

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Aerodynamic Performance Analysis of a Building-Integrated Savonius Turbine

Energies ◽

10.3390/en13102636 ◽

2020 ◽

Vol 13 (10) ◽

pp. 2636

Author(s):

Zhaoyong Mao ◽

Guangyong Yang ◽

Tianqi Zhang ◽

Wenlong Tian

Keyword(s):

Performance Analysis ◽

Wind Energy ◽

Wind Turbine ◽

Wind Turbines ◽

New Technology ◽

Aerodynamic Performance ◽

Operating Conditions ◽

High Rise ◽

Turbine Performance ◽

Cfd Method

The building-integrated wind turbine is a new technology for the utilization of wind energy in cities. Previous studies mainly focused on the wind turbines mounted on the roofs of buildings. This paper discusses the performance of Savonius wind turbines which are mounted on the edges of a high-rise building. A transient CFD method is used to investigate the performance of the turbine and the interaction flows between the turbine and the building. The influence of three main parameters, including the turbine gap, wind angle, and adjacent turbines, are considered. The variations of the turbine torque and power under different operating conditions are evaluated and explained in depth. It is found that the edge-mounted Savonius turbine has a higher coefficient of power than that operating in uniform flows; the average Cp of the turbine under 360-degree wind angles is 92.5% higher than the turbine operating in uniform flows. It is also found that the flow around the building has a great impact on turbine performance, especially when the turbine is located downwind of the building.

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