Change search
ReferencesLink to record
Permanent link

Direct link
Hydrodynamic Shape Optimization of Trawl Doors with Three-Dimensional Computational Fluid Dynamics Models and Local Surrogates
KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
2014 (English)Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
Abstract [en]

Rising fuel prices have been inflating the operating costs of the fishing industry. Trawl doors are used to hold the fishing net open during trawling operations, and they have a great influence on the fuel consumption of vessels. Improvements in the design of trawl doors could therefore contribute significantly to increased fuel efficiency. An efficient optimization algorithm using two- and three-dimensional (2D and 3D) computational fluid dynamics (CFD) models is presented. Accurate CFD models, especially 3D, are computationally expensive. The direct use of traditional optimization algorithms, which often require a large number of evaluations, can therefore be prohibitive. The proposed method is iterative and uses low-order local response surface approximation models as surrogates for the expensive CFD model to reduce the number of iterations. The algorithm is applied to the design of two types of geometries: a typical modern trawl door, and a novel airfoil-shaped trawl door. The results from the 2D design optimization show that the hydrodynamic efficiency of the typical modern trawl door could be increased by 32%, and the novel airfoil-shaped trawl door by 13%. When the 2D optimum designs for the two geometries are compared, the novel airfoil-shaped trawl door results to be 320% more efficient than the optimized design of the typical modern trawl door. The 2D optimum designs were used as the initial designs for the 3D design optimization. The results from the 3D optimization show that the hydrodynamic efficiency could be increased by 6% for both the typical modern and novel airfoil-shaped trawl doors. Results from a 3D CFD analysis show that 3D flow effects are significant, where the values for drag are significantly underestimated in 2D CFD models.

Place, publisher, year, edition, pages
2014. , 217 p.
Keyword [en]
Trawl door, hydrodynamics, optimization, SBO, CFD, local surrogates, response surfaces.
National Category
Energy Engineering
URN: urn:nbn:se:kth:diva-147352OAI: diva2:729779
Subject / course
Mechanical Engineering
Educational program
Master of Science - Sustainable Energy Engineering
2014-06-17, HPT Library, Brinellvägen 68, Stockholm, 09:45
Available from: 2014-07-22 Created: 2014-06-26 Last updated: 2014-07-22Bibliographically approved

Open Access in DiVA

Hermannsson_Elvar_EGI-2014-043MSC_EKV1028(23086 kB)258 downloads
File information
File name FULLTEXT01.pdfFile size 23086 kBChecksum SHA-512
Type fulltextMimetype application/pdf

Search in DiVA

By author/editor
Hermannsson, Elvar
By organisation
Heat and Power Technology
Energy Engineering

Search outside of DiVA

GoogleGoogle Scholar
Total: 258 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 202 hits
ReferencesLink to record
Permanent link

Direct link