Correction of aerodynamic influence matrices for transonic flow

Thormann, Reik; Dimitrov, Diliana

doi:10.1007/s13272-014-0114-3

Cited by 12 publications

(5 citation statements)

References 9 publications

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“…The DLM correction method CorrREcting Aerodynamic Matrices (CREAM) [23] was developed to improve predictions for unsteady aerodynamic loads. In addition to a quasi-steady correction (CREAM-0) an unsteady support point can be considered (CREAM-1).…”

Section: Correction To the Doublet Lattice Methodsmentioning

confidence: 99%

DLR project Digital-X: towards virtual aircraft design and flight testing based on high-fidelity methods

et al. 2015

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Numerical simulation is already an important cornerstone for aircraft design, although the application of highly accurate methods is mainly limited to the design point. To meet future technical, economic and social challenges in aviation, it is essential to simulate a real aircraft at an early stage, including all multidisciplinary interactions covering the entire flight envelope, and to have the ability to provide data with guaranteed accuracy required for development and certification. However, despite the considerable progress made there are still significant obstacles to be overcome in the development of numerical methods, physical modeling, and the integration of different aircraft disciplines for multidisciplinary analysis and optimization of realistic aircraft configurations. At DLR, these challenges are being addressed in the framework of the multidisciplinary project Digital-X (4/ 2012-12/2015). This paper provides an overview of the project objectives and presents first results on enhanced disciplinary methods in aerodynamics and structural analysis, the development of efficient reduced order methods for load analysis, the development of a multidisciplinary optimization process based on a multi-level/variable-fidelity approach, as well as the development and application of multidisciplinary methods for the analysis of maneuver loads.

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Section: Correction To the Doublet Lattice Methodsmentioning

confidence: 99%

DLR project Digital-X: towards virtual aircraft design and flight testing based on high-fidelity methods

et al. 2015

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“…Since the 1970s, potential-theory-based methods were used as cornerstones in aircraft industry, where one of them is the unsteady linear Doublet-Lattice method (DLM) [4]. Some of the method's deficiencies can be eliminated easily using one of numerous DLMcorrections [1,[5][6][7][8][9][10]. In this way their short computational time can be preserved, which is of paramount importance during an industrial design process.…”

Section: Introductionmentioning

confidence: 99%

Numerical Simulations on Unsteady Nonlinear Transonic Airfoil Flow

Friedewald

2020

Aerospace

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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.

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“…The range of theory applied to the problem is wide and includes approaches based on eigen realisation algorithms (ERAs) [1,2], Proper Orthogonal Decomposition (POD) [3], Volterra theory [4], and surrogates [5,6]. In potential flow, recent efforts have been focussed on the doublet lattice method [7,8]. Kriging [9] -a particularly useful tool in the field -is often used as the basis for aerodynamic surrogates [10][11][12][13].…”

Section: Introductionmentioning

confidence: 99%

A Kriging Based Corrected Potential Flow ROM for Gust Load Calculations

Horwitz

Man

Malan

et al. 2018

2018 Applied Aerodynamics Conference

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A novel aerodynamics reduced order model (ROM) is proposed for gust load calculations on two-and three-dimensional wing geometries at transonic flow conditions. Force estimates from sectional potential flow solutions are taken as inputs to kriging models that predict the aerodynamic loads. The kriging models are trained with coupled aeroelastic CFD calculations of two gust lengths (viz. short and long) which define a range in which the ROM is applicable. An interface is developed to handle the coupling of fluid and structure in the training simulations. The interface ensures conservative transfer of forces from the fluid to the structure and reconstruction of the fluid mesh subject to structural motion. Two test cases are put forward as a means to evaluate ROM: the FFAST Crank aerofoil and the NASA Common Research Model (CRM). In the former case, individual run cost decreased by an order of magnitude and error in the aeroelastic response never exceeded 8%. At the time of writing, the CFD calculations for the CRM case are underway.

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Correction of aerodynamic influence matrices for transonic flow

Cited by 12 publications

References 9 publications

DLR project Digital-X: towards virtual aircraft design and flight testing based on high-fidelity methods

DLR project Digital-X: towards virtual aircraft design and flight testing based on high-fidelity methods

Numerical Simulations on Unsteady Nonlinear Transonic Airfoil Flow

A Kriging Based Corrected Potential Flow ROM for Gust Load Calculations

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