Hayriye Pehlivan Solak

Accurate simulations of the flow around lifting hydrofoils are challenging, since they need to capture the flow near the foil surface precisely, represent the free surface, and take into account body motion and deformation. Therefore, these simulations are often computationally expensive. This paper studies numerical methods to limit the costs of h...

This paper studies the estimation of the uncertainty for stochastic RBF multi-fidelity surrogate models, focusing on two issues: limited numbers of data points (which is typical for surrogate models based on numerical simulation results) and noisy data. For the first issue, a default uncertainty is proposed which completes the SRBF estimation. Fo...

Lifting hydrofoils are gaining importance, since they drastically reduce the wetted surface area of a ship hull, thus decreasing resistance. To attain efficient hydrofoils, the geometries can be obtained from an automated optimization process, based on simulations. However, hydrofoil high-fidelity simulations are computationally demanding, since fi...

The paper presents and discusses the shape optimization of a destroyer-type vessel by means of several multi-fidelity approaches. The hull-form design (bare hull) of the DTMB 5415 model (an open-to-public concept used in the development of the DDG-51, the lead vessel of the Arleigh Burke-class guided missile destroyers) is addressed for optimal res...

Simulation-driven shape optimization often uses surrogate models, i.e. approximate models fitted through a dataset of simulation results for a limited number of designs. For efficiency, modern approaches often construct the datasets adaptively. The uncertainty estimation of the surrogate model is essential to guide the choice of new sample points...

A multi-fidelity surrogate modelling approach for shape optimization, which relies on adaptive techniques to obtain good performance for a large range of problems, is presented and critically evaluated. Furthermore, an approach to adaptive selection of the fidelity levels to be used is presented. Adaptation is shown to be effective for solving comp...

The paper presents a collection of analytical benchmark problems specifically selected to provide a set of stress tests for the assessment of multifidelity optimization methods. In addition, the paper discusses a comprehensive ensemble of metrics and criteria recommended for the rigorous and meaningful assessment of the performance of multifidelity...

The paper presents and discusses the so-called L3 sea benchmark problems used to develop and assess multi-fidelity optimization methods for military vehicle design within the AVT-331 Research Task Group on “Goal-driven, multi-fidelity approaches for military vehicle system-level design.” The hull-form design (bare hull) of the DTMB 5415 model (an o...

Uncertainty quantification has proven to be an indispensable study for enhancing reliability and robustness of engineering systems in the early design phase. Single and multi-fidelity surrogate modelling methods have been used to replace the expensive high fidelity analyses which must be repeated many times for uncertainty quantification. However,...

Advanced applications of multi-fidelity surrogate modelling techniques provide significant improvements in optimization and uncertainty quantification studies in many engineering fields. Multi-fidelity surrogate modelling can efficiently save the design process from the computational time burden caused by the need for numerous computationally expen...

The paper presents a collection of analytical benchmark problems specifically selected to provide a set of stress tests for the assessment of multifidelity optimization methods. In addition, the paper discusses a comprehensive ensemble of metrics and criteria recommended for the rigorous and meaningful assessment of the performance of multifidelity...

Surrogate (metamodel) based optimization has numerous potential applications in the field of naval architecture. It is aimed here to establish a methodology for the aft form optimization for minimum viscous resistance, thus the present study is focused on the aft form where the viscous effects become dominant. It is necessary to solve this problem...