Drag reduction of airplane fuselages through shaping by the inverse method

Zedan, M. F.; Seif, A.; Al-Moufadi, S.

doi:10.2514/3.46485

Cited by 20 publications

(13 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These experiments proved using non-separated shapes could improve vehicle performance effectively. Specially shaped bodies optimized for reducing drag calculated and tested in [9][10][11][12][13][14][15]. Ref.…”

Section: Introductionmentioning

confidence: 99%

Comparison of design methods for negative pressure gradient rotary bodies: A CFD study

Liu

Yang

et al. 2020

PLoS ONE

View full text Add to dashboard Cite

Computational fluid dynamics (CFD) simulation is used to test two body design methods which use negative pressure gradient to suppress laminar flow separation and drag reduction. The steady-state model of the Transition SST model is used to calculate the pressure distribution, wall shear stress, and drag coefficient under zero angle of attack at different velocities. Four bodies designed by two different methods are considered. Our results show the first method is superior to the body of Hansen in drag reduction and the body designed by the first method is more likely to obtain the characteristics of suppressing or eliminating separation, which can effectively improve laminar flow coverage to achieve drag reduction under higher Reynolds number conditions. The results show that the negative pressure gradient method can suppress separation and drag reduction better than the second method. This successful design method is expected to open a promising prospect for its application in the design of small drag, small noise subsonic hydrodynamic hull and underwater weapons.

show abstract

Section: Introductionmentioning

confidence: 99%

Comparison of design methods for negative pressure gradient rotary bodies: A CFD study

Liu

Yang

et al. 2020

PLoS ONE

View full text Add to dashboard Cite

show abstract

“…The theoretical drag on different bodies of revolution calculated in Parsons et al, [8], Dodbele et al, [9], Zedan et al [10], and Lutz & Wagner [11] are rather different and significantly exceed the estimation (1). For example, in [10] In the case of the attached flow pattern, slender bodies of revolution can delay laminarturbulent transitions on their surfaces and reduce the skin-friction drag. The corresponding critical values of the Reynolds number are estimated in [6,12].…”

Section: Introductionmentioning

confidence: 87%

Testing a Special Shaped Body of Revolution Similar to Dolphins Trunk

Nesteruk¹,

Brühl²,

Moeller³

2018

Nauk. Visti KPI

View full text Add to dashboard Cite

Background. The high swimming velocities of some aquatic animals such as dolphins continue to attract great interest of researchers. The friction drag of the dolphin, estimated with the use of turbulent friction coefficient of the flat plate, was so high to declare that the dolphin should not be able to swim as fast as it does with the muscle power it possesses. Some previous tests of the rigid bodies, similar to the animal shapes, and gliding dolphins revealed the attached flow patterns. Nevertheless, the researchers connected with industrial applications believe that separation is inevitable on every smooth shape, provided no active boundary-layer control methods (e.g., suction) are applied. Objective. The aim of the paper is to test a special shaped rigid body of revolution in the wind tunnel in order to show that the boundary-layer separation can be removed without any active flow control methods. Methods. Wind tunnel tests were carried out at velocities 15, 35, and 55 m/s. Static pressure measurements and the oil-flow visualization were used. For this study, we take the UA-2 special shaped model of 200 mm length and 56.78 mm of the maximum diameter. The closed version of the UA-2c model is similar to the dolphin body. The tests were carried out in the subsonic wind tunnel MUB of the Institut für Strömungsmechanik (ISM) at Technische Universität Braunschweig, Germany. The wind tunnel MUB of ISM is an actively cooled Goettingen type tunnel with a square section of 1.3 m and the turbulence level of about 0.2 %. The technique of oil-flow visualization was used to deliver information of the surface near flow. The color used is a mixture of thin mineral oil and petrol, in an optimized ratio. The very fine titan-dioxide particles and UV-light reactive polymer particles in the color deliver a high contrast picture of the flow directions with a high spatial resolution. Results. The distribution of the static pressure and the oil-flow visualization are presented at three angles of attack. The flow pattern at zero angle of attack is probably attached and laminar. Conclusions. Pressure measurements and the flow visualization on the special shaped body of revolution showed that it is probably possible to avoid separation in rather large range of the Reynolds numbers. Further experiments are necessary with the use of a visualization of the flow volume and hot-wire velocity probes to clarify the behavior of the boundary layer, its separation and laminar-to-turbulent transition characteristics.

show abstract

“…Nevertheless, the optimal shapes reported in [8] have a sufficiently higher fineness ratio. The theoretical values of the drag calculated in [8,14,15] [16]. Therefore, for 03 .…”

Section: Skin-friction Drag Of Slender Subsonic Axisymmetric Bodiesmentioning

confidence: 99%

Shape Optimization in High-Speed Hydro- And Aerodynamics to Prevent Separation and Cavitation

Nesteruk¹

2007

International Conference on Aerospace Sciences and Aviation Tec

View full text Add to dashboard Cite

The volumetric pressure drag for the standard supercavitating bodies (such as disc or cone) and for the cavitators with curvature was estimated. Analytic formulas for the skinfriction drag of the unseparated slender axisymmetric shapes are presented. It was shown that the main reserve of the drag reduction consists in using shapes providing the unseparated flow pattern. The volumetric drag coefficients for supercavitating and unseparated flow patterns were compared. It was shown that the standard supercavitating flow pattern is preferable for smaller values of the volumetric Reynolds number 7

show abstract

Drag reduction of airplane fuselages through shaping by the inverse method

Cited by 20 publications

References 14 publications

Comparison of design methods for negative pressure gradient rotary bodies: A CFD study

Comparison of design methods for negative pressure gradient rotary bodies: A CFD study

Testing a Special Shaped Body of Revolution Similar to Dolphins Trunk

Shape Optimization in High-Speed Hydro- And Aerodynamics to Prevent Separation and Cavitation

Contact Info

Product

Resources

About