Fluid flow and heat transfer in rotating curved duct at high rotation and density ratios

    Authors

    A. K. Sleiti;J. S. Kapat

    Comments

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    Abbreviated Journal Title

    J. Turbomach.-Trans. ASME

    Keywords

    TURBULENT BOUNDARY-LAYERS; STREAMLINE CURVATURE; 2ND-MOMENT CLOSURE; U-DUCTS; MODEL; COMPUTATION; BEND; Engineering, Mechanical

    Abstract

    Prediction of flow field and heat transfer of high rotation numbers and density ratio flow in a square internal cooling channels of turbine blades with U-turn as tested by Wagner et al. (ASME J. Turboinach., 113, pp. 42-51, 1991) is the main focus of this study. Rotation, buoyancy, and strong curvature affect the flow within these channels. Due to the fact that RSM turbulence model can respond to the effects of rotation, streamline curvature and anisotropy without the need for explicit modeling, it is employed for this study as it showed improved prediction compared to isotropic two-equation models. The near wall region was modeled using enhanced wall treatment approach. The Reynolds Stress Model (RSM) was validated against available experimental data (which are primarily at low rotation and buoyancy numbers). The model was then used for cases with high rotation numbers (as much as 1.29) and high-density ratios (up to 0.4). Particular attention is given to how secondary flow, velocity and temperature profiles, turbulence intensity, and Nusselt number area affected by Coriolis and buoyancy/centrifugal forces caused by high levels of rotation and buoyancy in the immediate vicinity of the bend. The results showed that four-side-average Nu, similar to low Ro cases, increases linearly by increasing rotation number and, unlike low Ro cases, decreases slightly by increasing density ratio.

    Journal Title

    Journal of Turbomachinery-Transactions of the Asme

    Volume

    127

    Issue/Number

    4

    Publication Date

    1-1-2005

    Document Type

    Article

    Language

    English

    First Page

    659

    Last Page

    667

    WOS Identifier

    WOS:000233121200002

    ISSN

    0889-504X

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