Numerical investigation of heat transfer and fluid flow in a rotating rectangular channel with variously-shaped discrete ribs

• A numerical study is performed to investigate the effects of various discrete rib configurations on the heat transfer and fluid flow characteristics of a rotating rectangular straight channel (aspect ratio of 2:1) with 45° orientation. Three parameters of the discrete rib configuration - rib streamwise distance, rib widthwise distance, and inner-half-rib angle - are examined based on a continuous inclined rib. The blockage ratio (e/Dh) is 0.1 and the pitch ratio (P/e) is 10. The Reynolds number is fixed at 10,000 in each case, while the rotation number is varied from 0 to 0.7. Details of the turbulent flow structure, turbulence kinetic energies, temperature fields, normalized Nusselt numbers, friction penalties and thermal performance factors were obtained by Computation of Fluid Dynamics (CFD) with the k-ω SST turbulence model. The results show that a small streamwise rib gap can effectively enhance the leading wall heat transfer. The heat transfer decreases gradually as the streamwise rib gap is enlarged. The inner-half-rib angle β provides the most conspicuous effects on heat transfer and friction loss, and the best heat transfer appears at β = 60° or 75° for different rotating conditions. The case with a rib streamwise gap normalized distance of 0.2 and inner-half-rib angle of 45° provides best thermal performance. A widthwise rib gap is favorable in reducing pressure drop, but its heat transfer augmentation is limited.

Ämnesord

TEKNIK OCH TEKNOLOGIER  -- Maskinteknik -- Energiteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Mechanical Engineering -- Energy Engineering (hsv//eng)

Nyckelord

Channel orientation

Coriolis force

Discrete rib

Heat transfer

Numerical simulation

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