Thermalhydraulic Analysis of Four Geometrical Design Parameters in Rib-Roughened Channels

Abstract

The present article reports RANS simulations of the flow and heat transfer in a 2-dimensional rib-roughened passage. The effects of four different geometrical factors including rib profile, rib pitch-to-height ratio, rib height, and rib width are investigated. The Reynolds number, based on the channel bulk velocity and hydraulic diameter, is 30,000. Two low-Reynolds-number linear EVMs, namely the Menter k-ω-SST model and a variant of Durbin's v ²-f formulation, are examined. All computations are undertaken using the commercial CFD code STAR-CD. In comparison with experimental data, it emerges that the v ²-f model generally returns more accurate results than the k-ω-SST closure.

Acknowledgments

This work was carried out as part of the UK Engineering and Physical Sciences Research Council Towards a Sustainable Energy Economy (TSEC) programme Keeping the Nuclear Option Open (KNOO), now extended by the Council's PhD+ fellowship scheme. As such, the author is grateful to EPSRC for funding under grant EP/C549465/1 and for the PhD+ award. Dr. S. A. Fairbairn of British Energy kindly supplied information concerning AGR design and operating conditions. Finally, the lead author is pleased to acknowledge the value in discussions with his colleagues Dr. M. A. Cotton, Dr. Y. Addad and Professor D. Laurence.

Notes

¹see, for example, A. Keshmiri, Three-Dimensional Simulation of Simplified Advanced Gas-Cooled Reactor Fuel Elements, J. Nuclear Engineering Design (under review).

*SRP = Square rib profile and MSRP = Multi-start rib profile.

²The reader is referred to www.CFDtm.org for results of some of the cross-code validation tests carried out by the authors and their colleagues.

*Rib width at half rib height.

**Exact value depending upon whether pitch is measured normal to the ribs or in the axial direction.