Computational-budget-driven automated microwave design optimization using variable-fidelity electromagnetic simulations

2012 ◽  
Vol 23 (3) ◽  
pp. 349-356 ◽  
Author(s):  
Slawomir Koziel ◽  
Stanislav Ogurtsov
Keyword(s):  
Design Optimization ◽  
Electromagnetic Simulations ◽  
Variable Fidelity ◽  
Microwave Design ◽  
Computational Budget

scholarly journals Cost-efficient Microwave Design Optimization Using Adaptive Response Scaling

2016 ◽  
Vol 80 ◽  
pp. 1042-1050
Author(s):  
Slawomir Koziel ◽  
Adrian Bekasiewicz ◽  
Leifur Leifsson
Keyword(s):  
Design Optimization ◽  
Adaptive Response ◽  
Microwave Design ◽  
Cost Efficient

Numerical Optimization Methods for Ship Hydrodynamic Design

2009 ◽  
Author(s):  
Emilio F. Campana ◽  
Daniele Peri ◽  
Yusuke Tahara ◽  
Manivannan Kandasamy ◽  
Frederick Stern
Keyword(s):  
Design Optimization ◽  
Optimization Problems ◽  
Substantial Reduction ◽  
Noise Robustness ◽  
Naval Research ◽  
Mathematical Framework ◽  
Original Design ◽  
Computational Expense ◽  
Ship Hydrodynamic ◽  
Variable Fidelity

The use of computational methods in design engineering is growing rapidly at all stages of the design process, with the final goal of a substantial reduction of the cost and time for the development of a design. Simulations and optimization algorithms can be combined together into what is known as Simulation-Based Design (SBD) techniques. Using these tools the designers may find the minimum of some user defined objective functions with constraints, under the general mathematical framework of a Non-Linear Programming problem. There are problems of course: computational complexity, noise, robustness and accuracy of the numerical simulations, flexibility in the use of these tools; all these issues will have to be solved before the SBD methodology can become more widespread. In the paper, some derivative-based algorithms and methods are initially described, including efficient ways to compute the gradient of the objective function. Derivative-free methods - such as genetic algorithms and swarm methods are then described and compared on both algebraic tests and on hydrodynamic design problems. Both local and global hydrodynamic ship design optimization problems are addressed, defined in either a single- or a multi-objective formulation framework. Methods for reducing the computational expense are presented. Metamodels (or surrogated models) are a rigorous framework for optimizing expensive computer simulations through the use of inexpensive approximations of expensive analysis codes. The Variable Fidelity idea tries instead to alleviate the computational expense of relying exclusively on high-fidelity models by taking advantage of well-established engineering approximation concepts. Examples of real ship hydrodynamic design optimization cases are given, reporting results mostly collected through a series of projects funded by the Office of Naval Research. Whenever possible, an experimental check of the success of the optimization process is always advisable. Several examples of this testing activity are reported in the paper one is illustrated by the two pictures at the top of this page, which show the wave pattern close to the sonar dome of an Italian Navy Anti-Submarine Warfare corvette: left, the original design; right, the optimized one.

Design Optimization of Off-Chip Inductors

2003 ◽  
Author(s):  
Lin Jin ◽  
Albert Chee W. Lu ◽  
Lai L. Wai ◽  
Wei Fan ◽  
Aik Chong Tan ◽  
...  
Keyword(s):  
Design Optimization ◽  
Manufacturing Process ◽  
Design Methodology ◽  
Solution Space ◽  
Operating Frequency ◽  
Wafer Level ◽  
Space Design ◽  
Electromagnetic Simulations

A solution space design methodology is presented for optimization of off-chip inductors. The analysis has been performed for an advanced wafer level redistribution manufacturing process. Electromagnetic simulations were performed to extract the characteristics of different inductor designs. It was observed that the design optimization should be tuned to the operating frequency.

Rapid design optimization of antennas using variable-fidelity EM models and adjoint sensitivities

2016 ◽  
Vol 33 (7) ◽  
pp. 2007-2018 ◽  
Author(s):  
Slawomir Koziel ◽  
Adrian Bekasiewicz
Keyword(s):  
Design Optimization ◽  
Optimization Technique ◽  
Computational Cost ◽  
Trust Region ◽  
Simulation Models ◽  
Direct Optimization ◽  
Content Type ◽  
Variable Fidelity ◽  
Em Simulation ◽  
Conventional Methods

Purpose Development of techniques for expedited design optimization of complex and numerically expensive electromagnetic (EM) simulation models of antenna structures validated both numerically and experimentally. The paper aims to discuss these issues. Design/methodology/approach The optimization task is performed using a technique that combines gradient search with adjoint sensitivities, trust region framework, as well as EM simulation models with various levels of fidelity (coarse, medium and fine). Adaptive procedure for switching between the models of increasing accuracy in the course of the optimization process is implemented. Numerical and experimental case studies are provided to validate correctness of the design approach. Findings Appropriate combination of suitable design optimization algorithm embedded in a trust region framework, as well as model selection techniques, allows for considerable reduction of the antenna optimization cost compared to conventional methods. Research limitations/implications The study demonstrates feasibility of EM-simulation-driven design optimization of antennas at low computational cost. The presented techniques reach beyond the common design approaches based on direct optimization of EM models using conventional gradient-based or derivative-free methods, particularly in terms of reliability and reduction of the computational costs of the design processes. Originality/value Simulation-driven design optimization of contemporary antenna structures is very challenging when high-fidelity EM simulations are utilized for performance utilization of structure at hand. The proposed variable-fidelity optimization technique with adjoint sensitivity and trust regions permits rapid optimization of numerically demanding antenna designs (here, dielectric resonator antenna and compact monopole), which cannot be achieved when conventional methods are of use. The design cost of proposed strategy is up to 60 percent lower than direct optimization exploiting adjoint sensitivities. Experimental validation of the results is also provided.

Variable-fidelity shape optimization of dual-rotor wind turbines

2018 ◽  
Vol 35 (7) ◽  
pp. 2514-2542
Author(s):  
Andrew Thelen ◽  
Leifur Leifsson ◽  
Anupam Sharma ◽  
Slawomir Koziel
Keyword(s):  
Design Optimization ◽  
Wind Turbines ◽  
Computational Cost ◽  
Optimization Techniques ◽  
Fast Variable ◽  
Efficient Design ◽  
Content Type ◽  
Optimization Framework ◽  
Derivative Free ◽  
Variable Fidelity

Purpose Dual-rotor wind turbines (DRWTs) are a novel type of wind turbines that can capture more power than their single-rotor counterparts. Because their surrounding flow fields are complex, evaluating a DRWT design requires accurate predictive simulations, which incur high computational costs. Currently, there does not exist a design optimization framework for DRWTs. Since the design optimization of DRWTs requires numerous model evaluations, the purpose of this paper is to identify computationally efficient design approaches. Design/methodology/approach Several algorithms are compared for the design optimization of DRWTs. The algorithms vary widely in approaches and include a direct derivative-free method, as well as three surrogate-based optimization methods, two approximation-based approaches and one variable-fidelity approach with coarse discretization low-fidelity models. Findings The proposed variable-fidelity method required significantly lower computational cost than the derivative-free and approximation-based methods. Large computational savings come from using the time-consuming high-fidelity simulations sparingly and performing the majority of the design space search using the fast variable-fidelity models. Originality/value Due the complex simulations and the large number of designable parameters, the design of DRWTs require the use of numerical optimization algorithms. This work presents a novel and efficient design optimization framework for DRWTs using computationally intensive simulations and variable-fidelity optimization techniques.

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