Analysis and Modeling of Flow through Wind Tunnel Porous Wall

Nambu, Taisuke; Hashimoto, Atsushi; Aoyama, Takashi; Satô, Tetsuya

doi:10.2514/6.2010-4858

Cited by 6 publications

(3 citation statements)

References 6 publications

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“…The permeable walls greatly affect the flow field, and hence they must be properly modeled. However, there was no reliable model for the porous wall which is suitable for the condition of transonic wind tunnel, and therefore authors created a new porous wall model 9,10 . Using this new model, the pressure distributions on the porous wall agree well with the measurements.…”

Section: Introductionmentioning

confidence: 99%

Numerical Analysis of Wind Tunnel Wall Interference on Two-dimensional Airfoil by New Porous Wall Model

Nambu

Hashimoto

Murakami

et al. 2012

30th AIAA Applied Aerodynamics Conference

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To analyze wall interference of a transonic wind tunnel, flows of two-dimensional airfoil with wind tunnel porous walls are computed by CFD and the new porous wall model. First, the computational results are validated by comparing with measurement. The porous wall model shows high accuracy enough to precisely simulate the wall interference. Effect of the wall interference is discussed by comparing two kinds of computational results with and without the wind tunnel wall. Wall interference by the porous wall is characterized by the downwash and blockage. Porous wall is effective for decreasing the blockage, which causes the acceleration around the airfoil. However, high porosity of the porous wall causes the large downwash, and it changes incidence angle of the airfoil. The Mokry's correction method for wall interference is verified by applying the correction to CFD results. The Mokry's method shows high accuracy in subsonic and no stall conditions, which meet the requirement of small perturbation potential equation. The accuracy is also high even if the model is large relative to the wind tunnel size. However, about 10 drag count error is caused under the transonic flow. The accuracy is rapidly reduced around the stall condition, and over 100 count error is caused. Nomenclature= coordinate = velocity of x,y direction = flow angle ( ( )) [deg] = lift coefficient = drag coefficient = height of wind tunnel = chord length of airfoil = airfoil thickness = porosity (ration of hole to wall area) = angle of attack

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Section: Introductionmentioning

confidence: 99%

Numerical Analysis of Wind Tunnel Wall Interference on Two-dimensional Airfoil by New Porous Wall Model

Nambu

Hashimoto

Murakami

et al. 2012

30th AIAA Applied Aerodynamics Conference

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“…The porous wall is modeled by the relationship between flow rate and differential pressure through the wall. Details of the modeling method can be found in Nambu et al 5,6) In this study, the porous wall is modeled by the following equations:…”

Section: Porous Wall Modelmentioning

confidence: 99%

“…We have therefore developed a new porous wall model for transonic wind tunnels by analyzing the flow through a single hole using computational and experimental approaches. 5,6) This is the first model that can compute the effect of porous walls without requiring any empirical parameters. In our previous study, we attempted to apply the new model to compute the flow around a two-dimensional airfoil with wind tunnel walls.…”

Section: Introductionmentioning

confidence: 99%

Numerical Analysis of the ONERA-M6 Wing with Wind Tunnel Wall Interference

Nambu

Hashimoto

Aoyama

et al. 2015

Trans. Japan Soc. Aero. S Sci.

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The flow around an ONERA-M6 wing, including the effect of wind tunnel wall interference, is computed using CFD analysis with a porous wall model. The computational domain sets porous walls at the top and bottom of the wing section similar to actual wind tunnel experiments. The computational result captures almost the same shock wave shape as the wind tunnel. This could not be computed exactly in previous works that did not include wall effects. The interference of the porous walls reduces the Mach number and attack angle of the flow, and these effects alter the swept angle of front shock wave and the location of rear shock wave. The aerodynamics coefficients are also affected by the wall interference. The lift coefficient becomes smaller due to the reduction in attack angle. The lower Mach number decreases the drag coefficient, while the reduction in attack angle causes additional drag by a mechanism similar to induced drag.

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