0

Full Content is available to subscribers

Subscribe/Learn More  >

Adjoint Optimization of an Internal Cooling Channel U-Bend

[+] Author Affiliations
Sebastian Willeke, Tom Verstraete

von Karman Institute for Fluid Dynamics, Rhode-Saint-Genèse, Belgium

Paper No. GT2015-43423, pp. V05AT11A029; 13 pages
doi:10.1115/GT2015-43423
From:
  • ASME Turbo Expo 2015: Turbine Technical Conference and Exposition
  • Volume 5A: Heat Transfer
  • Montreal, Quebec, Canada, June 15–19, 2015
  • Conference Sponsors: International Gas Turbine Institute
  • ISBN: 978-0-7918-5671-0
  • Copyright © 2015 by ASME

abstract

This paper addresses the optimization of a two-dimensional U-bend passage of an internal serpentine cooling channel for reduced total pressure loss by means of a steepest-descent method. A steady-state incompressible flow is considered at a Reynolds number of 40,000 based on the bulk velocity at the domain inlet. The two-equation k-ε model is used for primal turbulence modeling. After only 30 design iterations, the gradient-based optimization results in a reduction of total pressure loss by 46% compared to the baseline geometry.

To obtain the required objective gradients efficiently, a continuous adjoint approach is implemented in the OpenFOAM environment. Adjoint governing equations and boundary conditions are derived from state equations for steady-state, incompressible, turbulent flows under the assumption of frozen turbulence. Two different methods are proposed for modifying the shape of internal and external curves defining the duct geometry. The first method makes use of direct displacement of boundary grid points, allowing for a wide design space. The second, novel parameterization utilizes a projection of the surface sensitivities to an underlying Bézier curve. In this case, the Bézier control points are used as design variables. A comparison of both methods demonstrates a slightly lower performance improvement by the Bézier-based approach due to the reduced design freedom. This approach has, however, several practical advantages.

Previous studies already addressed this optimization problem using gradient-free methods, but were limited in the degrees of freedom given to the shape variation. The present gradient-based optimization allows for a much larger design space and hence is used to compare the different methodologies. It shows that both optimizations result in similar shapes, although the gradient-based method allows for a slightly larger reduction in pressure loss due to the wider design space, while converging faster towards the optimum.

Copyright © 2015 by ASME
Topics: Cooling , Optimization

Figures

Tables

Interactive Graphics

Video

Country-Specific Mortality and Growth Failure in Infancy and Yound Children and Association With Material Stature

Use interactive graphics and maps to view and sort country-specific infant and early dhildhood mortality and growth failure data and their association with maternal

NOTE:
Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In