Enhanced heat transfer in a labyrinth channels with ribs of different shape

Research output: Contribution to journalArticle

Abstract

Purpose: The purpose of this study is to enhance the thermal performance in the labyrinth channel by different ribs shape. The labyrinth channel is a relatively new cooling structure to decrease the temperature near the trailing region of gas turbine. Design/methodology/approach: Based on the geometric similarity, a simplified geometric model is used. The k − ω turbulence model is used to close the Navier–Stokes equations. Five rib shapes (one rectangular rib, two arched ribs and two trapezoid ribs) and five Reynolds numbers (10,000 to 50,000) are considered. The Nusselt number, flow structure and friction factor are analyzed. Findings: Nusselt number is tightly related to the rib shape in the labyrinth channel. The different shapes of the ribs result in different horseshoe vortex and wake region. In general, the arched rib brings the highest Nusselt number and friction factor. The Nusselt number is increased by 15.8 per cent compared to that of trapezoidal ribs. High Nusselt number is accompanied by the high friction factor in a labyrinth channels. The friction factor is increased by 64.6 per cent compared to rectangular ribs. However, the rib shape has a minor effect on the overall thermal performance. Practical implications: This study is useful to protect the trailing region of advanced gas turbine. Originality/value: This paper presents the flow structure and heat transfer characteristics in a labyrinth channel with different rib shapes.

Details

Authors
Organisations
External organisations
  • Harbin Institute of Technology
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Energy Engineering

Keywords

  • Heat transfer, Labyrinth channel, Rib shape, Thermal performance, Vortex
Original languageEnglish
Pages (from-to)724-741
Number of pages18
JournalInternational Journal of Numerical Methods for Heat and Fluid Flow
Volume30
Issue number2
Early online date2019 Aug 19
Publication statusPublished - 2020
Publication categoryResearch
Peer-reviewedYes