An Investigative Study of Gurney Flaps on a NACA 0036 Airfoil

Altmann, Gregory F

doi:10.15368/theses.2011.44

Cited by 7 publications

(7 citation statements)

References 16 publications

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“…The study concluded that increase in the size of the Gurney flap leads to an increase in the lift coefficient for the sizes tested, also, it was noticed from the obtained data that the relationship between flap size and lift-curve shift does not seem to be linear. As an example, the increase in the lift coefficient between 0% and 0.5% chord length of the Gurney flap is higher than the increase in the lift coefficient due to changing the size of the Gurney flap from 1.5% and 2% chord length [6]. Adding a Gurney flap to the trailing edge of the wing not only increase the lift, but it also has a positive effect on delaying the separation on the suction surface.…”

Section: Introductionmentioning

confidence: 93%

Numerical Investigation for the Enhancement of the Aerodynamic Characteristics of an Aerofoil by Using a Gurney Flap

Al-Mawali¹

2017

GEOMATE

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Numerical investigation was carried out to determine the effect of a Gurney Flap on NACA 0012 aerofoil performance with emphasis on Unmanned Air Vehicles applications. The study examined different configurations of Gurney Flaps at high Reynolds number of = 3.6 × 10 5 in order to determine the optimal configuration. The Gurney flap was tested at different heights, locations and mounting angles. Compared to the clean aerofoil, the study found that adding the Gurney Flap increased the maximum lift coefficient by19%, 22%, 28%, 40% and 45% for the Gurney Flap height of 1%C, 1.5%C, 2%C, 3%C and 4%C respectively, C represents the chord of the aerofoil. However, it was also found that increasing the height of the gurney beyond 2%C leads to a decrease in the overall performance of the aerofoil due to the significant increase in drag penalty. Thus, the optimal height of the Gurney flap for the NACA 0012 aerofoil was found to be 2%C as it improves the overall performance of the aerofoil by 21%. As for the location, it was found that the lifting-enhanced effect of the gurney flap decreases as it is shifted towards the leading edge. Thus the optimal location of the Gurney Flap mounting was found to be at the trailing edge or at distances smaller than 10%C. The Gurney flap was also tested at different mounting angles of -45, 90 and +45 degrees and it was found that the Gurney flap at +45 mounting angle leads to the optimal performance of the aerofoil

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Section: Introductionmentioning

confidence: 93%

Numerical Investigation for the Enhancement of the Aerodynamic Characteristics of an Aerofoil by Using a Gurney Flap

Al-Mawali¹

2017

GEOMATE

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“…For a complete description of the inlet remanufacture, see the Appendices of Greg Altmann's paper. 13 Following the completion of the new flow straightener, the flow quality of the wind tunnel was measured. 14 The project was a senior project by three students.…”

Section: Cal Poly Wind Tunnel Recent Modificationsmentioning

confidence: 99%

An Experimental Investigation of a Goldschmied Propulsor

Roepke¹

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A wind tunnel investigation of an axisymmetric bluff body, known as a Goldschmied propulsor, was completed. This model conceptually combines boundary layer control and boundary layer ingestion into a single complementary system that is intended to use energy to reduce the axial force on the body by eliminating separation and increasing the pressure recovery aft of the body's maximum thickness. The goal of the current project was to design, fabricate, and fully document the performance of a wind tunnel model incorporating the Goldschmied propulsor concept and complete an examination of its aerodynamic performance. The investigation took place at

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“…Greg Altmanns's wind tunnel test (19) , previous to any of the Goldschmied testing, found that they were getting results that…”

Section: Recent Tunnel Modificationsmentioning

confidence: 99%

“…The standard k -ε model can be seen below: ( 18 ) and ( 19 ) where is the generation of turbulent kinetic energy due to velocity gradients, is generation due to buoyancy kinetic energy, and is the contribution of fluctuating dilatation in compressible turbulence. The standard k -ε model has weakness that has led to modifications to improve the model.…”

Section: K -ε Modelmentioning

confidence: 99%

Analysis of a Goldschmied Propulsor Using Computational Fluid Dynamics Referencing California Polytechnic’s Goldschmied Propulsor Testing

Seubert¹

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The Goldschmied Propulsor is a concept that was introduced in mid 1950's by Fabio Goldschmied. The concept combines boundary layer suction and boundary layer ingestion technologies to reduce drag and increase propulsor efficiency. The most recent testing, done in 1982, left questions concerning the validity of the results. To answer these questions a 38.5in Goldschmied Propulsor was constructed and tested in Cal Poly's 3x4ft wind tunnel. The focus of their wind tunnel investigation was to replicate Goldschmied's original testing and increase the knowledge base on the subject. The goal of this research was to create a computational fluid dynamics (CFD) model to help visualize the flow phenomenon and see how well CFD was able to replicate Cal Poly's wind tunnel results. CFD cases were run to get a comparison of the computational model and the wind tunnel results. For the straight tunnel geometry for the 0.385" slot and cusp A we found a body, pressure and friction drag, fan off C D of 0.0526 and a fan on at 500 Pascals with a C D of 0.0545. This is similar to the wind tunnel results but because of large errors in measuring overall drag we are not able to directly compare to the wind tunnel results. Overall we see that the trends match, mainly that the fan does not decrease the total pressure drag. This was a result of poor geometry and high fan speeds needed for attachment. The tested geometry is less than ideal and has a long way to go before it is of a shape that would have the potential to reduce the pressure drag as much as Goldschmied claimed. Future efforts should be put forth optimizing the aft body to reduce the low pressure in front of the slot and improving aft entrance of the slot to allow for a smoother flow.v ACKNOWLEDGMENTS

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An Investigative Study of Gurney Flaps on a NACA 0036 Airfoil

Cited by 7 publications

References 16 publications

Numerical Investigation for the Enhancement of the Aerodynamic Characteristics of an Aerofoil by Using a Gurney Flap

Numerical Investigation for the Enhancement of the Aerodynamic Characteristics of an Aerofoil by Using a Gurney Flap

An Experimental Investigation of a Goldschmied Propulsor

Analysis of a Goldschmied Propulsor Using Computational Fluid Dynamics Referencing California Polytechnic’s Goldschmied Propulsor Testing

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