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Chapter
Optimal Separation Control on the Flap of a 2D High-Lift Configuration
Flow separation on the flap of a high-lift device degrades the overall aerodynamic performance and hence results in a drop in the lift coefficient. However, by employing the active flow control techniques, sep...
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Chapter
Extension of the One-Shot Method for Optimal Control with Unsteady PDEs
The one-shot approach has proven to be very efficient in optimization and control with steady partial differential equations (PDEs) which are solved by fixed-point iterations. The purpose of this paper is to e...
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Chapter
One-Shot Approaches to Design Optimzation
The paper describes general methodologies for the solution of design optimization problems. In particular we outline the close relations between a fixed point solver based piggy back approach and a Reduced SQP...
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Chapter
Optimal Design with Bounded Retardation for Problems with Non-separable Adjoints
In the natural and enginiering sciences numerous sophisticated simulation models involving PDEs have been developed. In our research we focus on the transition from such simulation codes to optimization, where...
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Chapter
A Discrete Adjoint Approach for Unsteady Optimal Flow Control
In this paper, we present a discrete adjoint method for optimal flow control of unsteady incompressible viscous flows. The discrete adjoint solver is developed in an automatic fashion from the flow solver by a...
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Chapter and Conference Paper
Optimal Control of Unsteady Flows Using a Discrete and a Continuous Adjoint Approach
While active flow control is an established method for controlling flow separation on vehicles and airfoils, the design of the actuation is often done by trial and error. In this paper, the development of a di...
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Chapter
Quantification and Reduction of Numerical Uncertainties by Improvement of the TAU Grid Adaptation Tool and Adjoint Methods
Within the framework of the project MUNA, several enhancements of the grid adaptation tool of the DLR TAU Code were prepared, implemented and tested. Therefore, various quality aspects of the single elements o...
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Chapter and Conference Paper
Application of Automatic Differentiation to an Incompressible URANS Solver
This paper deals with the task of generating a discrete adjoint solver from a given primal Unsteady Reynolds Averaged Navier-Stokes (URANS) solver for incompressible flows. This adjoint solver is to be employe...
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Article
Airfoil design for compressible inviscid flow based on shape calculus
Aerodynamic design based on the Hadamard representation of shape gradients is considered. Using this approach, the gradient of an objective function with respect to a deformation of the shape can be computed a...
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Chapter and Conference Paper
An Efficient One-Shot Algorithm for Aerodynamic Shape Design
In this paper we consider the shape optimization of a transonic airfoil whose aerodynamic properties are calculated by a structured Euler solver. The optimization strategy is based on a one-shot technique in w...
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Chapter and Conference Paper
Adjoint Methods for Coupled CFD-CSM Optimization
Multi-disciplinary analysis is necessary to reach physically meaningful optimum designs. For aero-structural shape optimization this means coupling two disciplines – aerodynamics and structural mechanics. In t...
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Chapter and Conference Paper
Single-step One-shot Aerodynamic Shape Optimization
In this paper we consider the shape optimization of a transonic airfoil whose aerodynamic properties are calculated by a structured Euler solver. The optimization strategy is based on a one-shot technique in w...
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Chapter and Conference Paper
Differentiating Fixed Point Iterations with ADOL-C: Gradient Calculation for Fluid Dynamics
The reverse mode of automatic differentiation allows the computation of gradients at a temporal complexity that is only a small multiple of the temporal complexity to evaluate the function itself. However, the...
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Chapter and Conference Paper
Automatic Differentiation of an Entire Design Chain for Aerodynamic Shape Optimization
Detailed numerical shape optimization will play a strategic role for future aircraft design. It offers the possibility of designing or improving aircraft components with respect to a pre-specified figure of me...
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Chapter
Efficient Deterministic Approaches for Aerodynamic Shape Optimization
Because detailed aerodynamic shape optimizations still suffer from high computational costs, efficient optimization strategies are required. Regarding the deterministic optimization methods, the adjoint approa...
