3D Shape Optimization of Consecutive Manifolds using Free Form Deformation and Adjoint-Based Methods

Current design methods for oblique manifolds were first presented in the paper of London et al. in 1968. This method presents a single equation to shape the dividing manifold of several manifold configurations. However, current literature shows a potential to improve the current design method by implementing advanced techniques. This paper aims...

The application of differentiable programming frameworks to computational fluid dynamics

In recent years many automatic differentiable programming frameworks have been developed in which numerical programs can be differentiated through automatic differentiation (AD). Examples of these frameworks are Theano, TensorFlow and Pytorch. These frameworks are widely used in Machine Learning. AD also finds applications in the field of...

The role of PDE-based parameterization techniques in gradient-based IGA shape optimization applications

This paper proposes a shape optimization algorithm based on the principles of Isogeometric Analysis (IGA) in which the parameterization of the geometry enters the problem formulation as an additional PDE-constraint. Inspired by the isoparametric principle of IGA, the parameterization and the governing state equation are treated using the same...

Estimating NOx emissions using S5-P TROPOMI: An adjoint-free 4DVAR approach

This study aims to improve estimates of NOx emission strengths by assimilation of TROPOMI satellite retrievals in the LOTOS-EUROS chemical transport model. Nitrogen oxides (NO and NO2) play a pivotal role in atmospheric chemistry, are an important source of air pollution and contribute to nitrogen deposition over vulnerable natural areas....

Adjoint-Based Optimization through Reduced-Order Subdomain Surrogate Modelling: An Application in Reservoir Simulation

Although a transition to more sustainable energy production is necessary, fossil fuels will remain a crucial contributor to the world's energy production in the near future. In numerically maximizing the production of these fuels, as well as in many other optimization problems, an objective function has to be optimized on the basis of an input...

Adjoint-based 3D Shape Optimization for Turbomachinery Applications

In order to reduce the carbon foot-print of turbo-generators to global warming, a step-change in the design process is needed. Extensive CFD simulations coupled with optimization algorithms are required, resorting to novel techniques to capture the complex flow phenomena occurring in the passage. However, the computation of the optimization...