Multi-Fidelity Kriging Extrapolation: a novel surrogate modelling method for computer experiments using CFD, exploiting grid convergence

Surrogate modelling techniques such as Kriging are a popular means for cheaply emulating the response of expensive Computational Fluid Dynamics simulations. These surrogate models are often used for exploring a parameterised design space and identifying optimal designs. Multi-fidelity Kriging extends the methodology to incorporate data of...

Non-Intrusive Multi-Fidelity Reduced Order Modeling using Adaptive Sparse Grids: Analysis of Nuclear Reactors using Non-Intrusive Adaptive Multi-Fidelity Reduced Order Modeling Techniques

Computational power is a challenge when it comes to the high-fidelity modeling of nuclear reactors. Detailed simulations of reactor physics involve complex calculations that require significant computing resources, which can be time-consuming and expensive. Reduced Order Modeling (ROM) allows for an approximation of a complex model by only...

Aerodynamic assessment of sub-scale aircraft model: A multi-fidelity approach

Novel designs like the Flying-V, Prandtl-Plane and Blended Wing-Body show promise towards sustainable aviation. In the preliminary design phase, Sub-scale Flight Test (SFT) is a reliable method to get insight into the flight behavior of these designs. The effectiveness and value provided by SFT depends on the similitude between the SFT model and...

Early-stage design of novel vessels: How can we take a step forward?

The aim of this paper is to discuss the challenges associated with the early-stage design of novel and reliable vessels, and discuss some of the expected benefits of the application of multi-fidelity models in addressing some of their early-stage design problems. Traditionally, early-stage design tools are computationally cheap, but lack in...

The role of multi-fidelity modelling in adaptation and recovery of engineering systems

Significant research has been conducted in identifying optimal recovery and adaptation decisions in disruptive scenarios using engineering models. In this context, an aspect that has been target of limited research is that of response times. Modelling is expected to grow progressively more complex as it becomes more accurate. Such complexity...

Exploratory research on application Multi-Level Multi-Fidelity Monte Carlo in fluid dynamics topics: study on flow past a porous cylinder

In offshore engineering complex simulation models are constructed for design optimization using Monte Carlo methods. These models incur large computational costs. Multi-Level Multi-Fidelity Monte Carlo is proposed as a method to reduce the computational cost of these simulations. In addition, research is conducted on the use of porous media as...

Customized data-driven RANS closures for bi-fidelity LES–RANS optimization

Multi-fidelity optimization methods promise a high-fidelity optimum at a cost only slightly greater than a low-fidelity optimization. This promise is seldom achieved in practice, due to the requirement that low- and high-fidelity models correlate well. In this article, we propose an efficient bi-fidelity shape optimization method for...

Screening wave conditions for the occurrence of green water events on sailing ships

Design loads for extreme wave events on ships, such as slamming and green water, are hard to define. These events depend on details in the incoming waves, ship motions and structure layout, which requires high-fidelity tools such as CFD or experiments to obtain the correct loads. These tools (presently) do not have the capability to fully...

MultiTune: Dynamic budget allocation for hyperparameter tuning

Hyperparameter optimization(HPO) forms a critical aspect for machine learning applications to attain superior performance. BOHB (Bayesian Optimization and HyperBand) is a state of the art HPO algorithm that approaches HPO in a multi-armed bandit strategy, augmented with Bayesian optimization to drive configuration sampling. However, BOHB...

Surrogate Constitutive Models with Multi-fidelity Gaussian Processes for Composite Micromodels

Various engineering applications rely on efficient, high performance materials to overcome design challenges. This high performance can be achieved by engineering micro-heterogenous materials also known as composites. Since the behavior of composites relies heavily on micro-scale interactions between different components, modeling...

Design of Swirl Recovery Vanes for Wing-Mounted Tractor Propeller Propulsion System

Increasing pressure of reducing fuel consumption has led to renewed interests in propeller propulsion devices for their high propulsive efficiency. In a propeller propulsion system, the torque applied to the propeller results in angular momentum in propeller slipstream. This angular momentum is not only a form of energy loss that does not...

Multi-fidelity Method for Aerodynamic Optimisation of Axial Compressor Blades

In turbomachinery optimisation problems, run time is often a critical factor due to high dimensionality of the design search space. This work explores the use of the multi-fidelity method to speed up an aerodynamic optimisation algorithm applied to axial compressor blades. A rotor blade is optimised in a two-stage blade geometry for maximum...

Multi-fidelity wing aerostructural optimization using a trust region filter-SQP algorithm

A trust region filter-SQP method is used for wing multi-fidelity aerostructural optimization. Filter method eliminates the need for a penalty function, and subsequently a penalty parameter. Besides, it can easily be modified to be used for multi-fidelity optimization. A low fidelity aerostructural analysis tool is presented, that computes the...

Uncertainty Quantification for a Sailing Yacht Hull, Using Multi-Fidelity Kriging

Uncertainty Quantication (UQ) for CFD-based ship design can require a large number of simulations, resulting in signicant overall computational cost. Presently, we use an existing method, multi-delity Kriging, to reduce the number of simulations required for the UQ analysis of the performance of a sailing yacht hull, considering uncertainties in...

Multi-fidelity methods for fluid-structure interaction and uncertainty quantification

The cost and turnaround time of the load calculation cycle in the design process of aircraft can be reduced by developing new numerical simulation technologies aimed at efficient prediction of steady and unsteady force coefficients in the flight envelope. In order to capture the most extreme stress levels due to gust and manoeuvres, efficient...

Towards a Multi-Fidelity Approach for CFD Simulations of Vortex Generator Arrays

This paper is the starting point for the development of a multi-fidelity modeling approach for vortex generators (VG) arrays, where a fully resolved VG model will be coupled with an approximate model in order to improve both accuracy and flexibility without increasing the required computational cost. As a first step thereto, an analysis of the...