Numerical Simulations on Unsteady Nonlinear Transonic Airfoil Flow
Large-amplitude excitations need to be considered for gust load analyses of transport aircraft in cruise flight conditions. Nonlinear amplitude effects in transonic flow are, however, only marginally taken into account. The present work aims at closing this gap by means of systematic unsteady Reynol...
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| Format: | Article |
| Language: | English |
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MDPI AG
2020-12-01
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| Series: | Aerospace |
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| Online Access: | https://www.mdpi.com/2226-4310/8/1/7 |
| _version_ | 1797543227807498240 |
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| author | Diliana Friedewald |
| author_facet | Diliana Friedewald |
| author_sort | Diliana Friedewald |
| collection | DOAJ |
| description | Large-amplitude excitations need to be considered for gust load analyses of transport aircraft in cruise flight conditions. Nonlinear amplitude effects in transonic flow are, however, only marginally taken into account. The present work aims at closing this gap by means of systematic unsteady Reynolds-averaged Navier-Stokes simulations. The RAE2822 airfoil is analyzed for a variety of sinusoidal gust excitations at different transonic Mach numbers. Responses are evaluated with respect to lift and moment coefficients, their derivatives and the unsteady shock motion. A strong dependency on inflow Mach number and excitation frequency is observed. Generally, amplitude effects decrease with lower Mach numbers or higher excitation frequencies. The unsteady nonlinear simulations predict lower maximum lift values and lower lift and moment derivatives compared to their linear counterparts for lower frequencies in combination with large-amplitude excitations. For the mid-frequency range, trends are not as clear. Additionally, it is shown that the variables of harmonic distortion and maximum shock motion might not be reasonable indicators to predict a nonlinear response. |
| first_indexed | 2024-03-10T13:41:39Z |
| format | Article |
| id | doaj.art-6737187f2723412eaef4ce0a6b838342 |
| institution | Directory Open Access Journal |
| issn | 2226-4310 |
| language | English |
| last_indexed | 2024-03-10T13:41:39Z |
| publishDate | 2020-12-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Aerospace |
| spelling | doaj.art-6737187f2723412eaef4ce0a6b8383422023-11-21T02:58:44ZengMDPI AGAerospace2226-43102020-12-0181710.3390/aerospace8010007Numerical Simulations on Unsteady Nonlinear Transonic Airfoil FlowDiliana Friedewald0DLR (German Aerospace Center), Institute of Aeroelasticity, Bunsenstr. 10, 37073 Göttingen, GermanyLarge-amplitude excitations need to be considered for gust load analyses of transport aircraft in cruise flight conditions. Nonlinear amplitude effects in transonic flow are, however, only marginally taken into account. The present work aims at closing this gap by means of systematic unsteady Reynolds-averaged Navier-Stokes simulations. The RAE2822 airfoil is analyzed for a variety of sinusoidal gust excitations at different transonic Mach numbers. Responses are evaluated with respect to lift and moment coefficients, their derivatives and the unsteady shock motion. A strong dependency on inflow Mach number and excitation frequency is observed. Generally, amplitude effects decrease with lower Mach numbers or higher excitation frequencies. The unsteady nonlinear simulations predict lower maximum lift values and lower lift and moment derivatives compared to their linear counterparts for lower frequencies in combination with large-amplitude excitations. For the mid-frequency range, trends are not as clear. Additionally, it is shown that the variables of harmonic distortion and maximum shock motion might not be reasonable indicators to predict a nonlinear response.https://www.mdpi.com/2226-4310/8/1/7CFDURANStransonic flownonlinear aerodynamicsgust responseshock motion |
| spellingShingle | Diliana Friedewald Numerical Simulations on Unsteady Nonlinear Transonic Airfoil Flow Aerospace CFD URANS transonic flow nonlinear aerodynamics gust response shock motion |
| title | Numerical Simulations on Unsteady Nonlinear Transonic Airfoil Flow |
| title_full | Numerical Simulations on Unsteady Nonlinear Transonic Airfoil Flow |
| title_fullStr | Numerical Simulations on Unsteady Nonlinear Transonic Airfoil Flow |
| title_full_unstemmed | Numerical Simulations on Unsteady Nonlinear Transonic Airfoil Flow |
| title_short | Numerical Simulations on Unsteady Nonlinear Transonic Airfoil Flow |
| title_sort | numerical simulations on unsteady nonlinear transonic airfoil flow |
| topic | CFD URANS transonic flow nonlinear aerodynamics gust response shock motion |
| url | https://www.mdpi.com/2226-4310/8/1/7 |
| work_keys_str_mv | AT dilianafriedewald numericalsimulationsonunsteadynonlineartransonicairfoilflow |