0
Research Papers

# Numerical Predictions of the Effect of Rotation on Fluid Flow and Heat Transfer in an Engine-Similar Two-Pass Internal Cooling Channel With Smooth and Ribbed Walls

[+] Author and Article Information
M. Schüler1

Institut für Thermodynamik der Luft- und Raumfahrt (ITLR), Universität Stuttgart, Pfaffenwaldring 31, D-70569 Stuttgart, Germanymarco.schueler@siemens.com

H.-M. Dreher2

Institut für Thermodynamik der Luft- und Raumfahrt (ITLR), Universität Stuttgart, Pfaffenwaldring 31, D-70569 Stuttgart, Germanyhorst-michael.dreher@schulergroup.com

S. O. Neumann, B. Weigand

Institut für Thermodynamik der Luft- und Raumfahrt (ITLR), Universität Stuttgart, Pfaffenwaldring 31, D-70569 Stuttgart, Germany

M. Elfert

Institut für Antriebstechnik, Deutsches Zentrum für Luft- und Raumfahrt (DLR), Linder Höhe, D-51147 Köln, Germanymartin.elfert@dlr.de

1

Present address: Siemens AG, Energy Sector, Gas Turbine Engineering—Turbine Design, Mellinghofer Str. 55, D-45478 Mülheim an der Ruhr, Germany.

2

Present address: Müller Weingarten AG (SchulerGroup), Development Team Wind Power Stations, Schussenstraße 11, D-88250 Weingarten, Germany.

J. Turbomach 134(2), 021021 (Jun 30, 2011) (10 pages) doi:10.1115/1.4003086 History: Received August 04, 2010; Revised August 28, 2010; Published June 30, 2011; Online June 30, 2011

## Abstract

In the present study, a two-pass internal cooling channel with engine-similar cross-sections was investigated numerically. The channel featured a trapezoidal inlet pass, a sharp 180 deg bend, and a nearly rectangular outlet pass. Calculations were done for a configuration with smooth walls and walls equipped with 45 deg skewed ribs $(P/e=10, e/dh=0.1)$ at a Reynolds number of $Re=50,000$. The present study focused on the effect of rotation on fluid flow and heat transfer. The investigated rotation numbers were $Ro=0.0$ and 0.10. The computations were performed by solving the Reynolds-averaged Navier–Stokes equations (Reynolds-averaged Navier–Stokes method) with the commercial finite-volume solver FLUENT using a low-Re shear stress transport (SST) $k-ω$ turbulence model. The numerical grids were block-structured hexahedral meshes generated with POINTWISE . Flow field measurements were independently performed at German Aerospace Centre Cologne using particle image velocimetry. In the smooth channel, rotation had a large impact on secondary flows. Especially, rotation induced vortices completely changed the flow field. Rotation also changed flow impingement on the tip and the outlet pass sidewall. Heat transfer in the outlet pass was strongly altered by rotation. In contrast to the smooth channel, rotation showed less influence on heat transfer in the ribbed channel. This is due to a strong secondary flow field induced by the ribs. However, in the outlet pass, Coriolis forces markedly affected the rib induced secondary flow field. The influence of rotation on heat transfer was visible in particular in the bend region and in the second pass directly downstream of the bend.

<>

## Figures

Figure 1

Schematic and geometry of the numerical model

Figure 2

Computational grid of the smooth two-pass channel

Figure 3

Computational grid of the ribbed two-pass channel

Figure 4

Velocity field in the smooth two-pass channel at (a) lower side at 0.12dS above bottom wall, (b) midplane (50% local channel height), and (c) upper side at 0.12dS below top wall

Figure 5

Influence of rotation on the secondary flow field of the smooth two-pass channel at (a) cut 1 at z=12.2dS (near channel entrance), (b) cut 2 at z=16dS (midchannel), and (c) cut 3 at z=19.96dS (directly before the bend)

Figure 6

Velocity field in the ribbed two-pass channel at (a) lower side at 0.12dS above bottom wall, (b) midplane (50% local channel height), and (c) upper side at 0.12dS below top wall

Figure 7

Influence of rotation on the secondary flow field of the ribbed two-pass channel at (a) cut 1 at z=12.2dS (near channel entrance), (b) cut 2 at z=16dS (midchannel), and (c) cut 3 at z=19.96dS (directly before the bend)

Figure 8

Local Nusselt number ratio distribution for the smooth two-pass configuration for (a) nonrotating case (Ro=0.0) and (b) rotating case (Ro=0.10)

Figure 9

Area-averaged Nusselt number ratio of the smooth two-pass channel in comparison with experimental data for Ro=0.0 from Schüler (41): (a) leading side, (b) trailing side, and (c) tip wall and sidewalls

Figure 10

Local Nusselt number ratio distribution for the smooth two-pass configuration for (a) nonrotating case (Ro=0.0) and (b) rotating case (Ro=0.10)

Figure 11

Area-averaged Nusselt number ratio of the ribbed two-pass channel in comparison with experimental data for Ro=0.0 from Schüler (41): (a) leading side, (b) trailing side, and (c) tip wall and sidewalls

## Discussions

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 Journal Articles
Related Proceedings Articles
Related eBook Content
Topic Collections