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ISSN Druckformat: 1065-5131
ISSN Online: 1563-5074
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PREDICTION OF FLOW AND HEAT TRANSFER INSIDE A TWO-PASS ROTATING CHANNEL WITH ANGLED RIBBED SURFACES
ABSTRAKT
Numerical predictions of three-dimensional flow and heat transfer are carried out for a rotating two-pass square channel with staggered angled ribs using a second-moment closure turbulence model (SMC). Two channel orientations (β = 0° and β = 45°), two rib orientations (α = -45° and α = +45°), and both rotation directions (Ω) are examined to simulate a turbine blade cooling circuit with forward flow of coolant (positive rotation) and with rearward flow of coolant (negative rotation). For a Reynolds number of 25,000, a density ratio of 0.13, and a rotation number of 0.24, the results show that at the cotrailing and coleading sides of the first passage for positive rotation, the secondary flows induced by -45° ribs and by rotation destructively combine, while the secondary flows generated by +45° ribs and by rotation constructively combine. For negative rotation, the secondary flows generated by -45° ribs and by rotation constructively combine in the first passage. In contrast, in the second passage the rotation affects significantly the secondary flow induced by +45° ribs as compared to that for positive rotation. The heat transfer rate depends directly on these interactions. Comparative studies of two rib orientations and flow direction suggest that the +45° ribs are preferable to enhance the heat transfer rate in the first passage with radially outward flow for forward flow of coolant, and the -45° ribs are preferable in the second passage with radially inward flow for rearward flow of coolant with an acceptable pressure drop. Numerical results are in fair agreement with available experimental data.
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Saha Sujoy Kumar, Ranjan Hrishiraj, Emani Madhu Sruthi, Bharti Anand Kumar, Active and Passive Techniques: Their Applications, in Introduction to Enhanced Heat Transfer, 2020. Crossref