Multi-objective optimization using evolutionary algorithms: Application to the control of flow past a circular cylinder

Bingham, Conrad Cole

Multi-objective optimization using evolutionary algorithms: Application to the control of flow past a circular cylinder

dc.contributor.advisor	Martinuzzi, Robert John
dc.contributor.advisor	Morton, Chris R.
dc.contributor.advisor	Hu, Yaoping
dc.contributor.author	Bingham, Conrad Cole
dc.contributor.committeemember	Ziadé, Paul
dc.contributor.committeemember	Westwick, David T.
dc.contributor.committeemember	Epstein, Marcelo D.
dc.date	2019-06
dc.date.accessioned	2018-12-03T16:22:06Z
dc.date.available	2018-12-03T16:22:06Z
dc.date.issued	2018-11-22
dc.description.abstract	Modifications to the vortex shedding dynamics from a circular cylinder of diameter D are investigated experimentally in a free surface water channel. The vortex shedding is modified via the placement of a control cylinder of diameter \textit{D}/8 in the vicinity of the main cylinder. A methodology is presented to link changes in the wake dynamics and loading on the main cylinder. The analysis combines Fourier Modal Decomposition, Proper Orthogonal Decomposition, and phase averaging. Based on differences in the wake dynamics, the influence of the control cylinder can be classified according to its placement: (i) in the free stream outside the main cylinder shear layer; (ii) within the main cylinder shear layer; and (iii) in the recirculation region. While fluctuating lift is significantly reduced in all cases, the mean and fluctuating drag are affected differently. A generalized model-free method to optimize parameters for open-loop and closed-loop control in fluid mechanics applications is then presented. A multi-objective evolutionary algorithm (MOEA) is employed to minimize the oscillating lift caused by vortex shedding from the main cylinder. The control cylinder is prescribed a position as well as a periodic motion in two dimensions. The MOEA efficiently handles the larger optimization parameter space. The first objective of the algorithm is to minimize the fluctuating force coefficient $C_{L_{RMS}}$, while the second objective is to minimize of the actuation power required to drive the control cylinder. The final solution suppresses $C_{L_{RMS}}$ by over 90\% using near-zero actuation power. Further, the MOEA automatically provides a sensitivity study as to the influence of the different parameters and also in which spatial area the greatest influence is expressed.	en_US
dc.identifier.citation	Bingham, C. C. (2018). Multi-objective optimization using evolutionary algorithms: Application to the control of flow past a circular cylinder (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/34666	en_US
dc.identifier.doi	http://dx.doi.org/10.11575/PRISM/34666
dc.identifier.uri	http://hdl.handle.net/1880/109214
dc.language.iso	eng
dc.publisher.faculty	Graduate Studies
dc.publisher.faculty	Schulich School of Engineering
dc.publisher.institution	University of Calgary	en
dc.publisher.place	Calgary	en
dc.rights	University of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.
dc.subject	Vortex Shedding
dc.subject	Machine Learning
dc.subject	Evolutionary Algorithms
dc.subject	Fluid Mechanics
dc.subject	Optimization
dc.subject	Multi-Objective
dc.subject.classification	Fluid and Plasma	en_US
dc.subject.classification	Computer Science	en_US
dc.subject.classification	Engineering--Aerospace	en_US
dc.subject.classification	Engineering--Mechanical	en_US
dc.subject.classification	Robotics	en_US
dc.title	Multi-objective optimization using evolutionary algorithms: Application to the control of flow past a circular cylinder
dc.type	master thesis
thesis.degree.discipline	Mechanical and Manufacturing Engineering
thesis.degree.grantor	University of Calgary
thesis.degree.name	Master of Science (MSc)
ucalgary.item.requestcopy	true