Mixed convection heat and mass transfer in radially rotating rectangular ducts
- Oriental Inst. of Tech., Taipei (Taiwan, Province of China). Dept. of Mechanical Engineering
- Huafan Univ., Taipei (Taiwan, Province of China). Dept. of Mechanical Engineering
Heat transfer in rotating ducts is encountered in many engineering applications, such as cooling of turbomachinery, gas turbines, and other rotating systems. The present work investigates mixed convection heat and mass transfer in the entrance region of radially rotating rectangular ducts with water film evaporation along the porous duct walls. Mechanisms of secondary vortex development in the ducts under various conditions are examined by a vorticity-velocity numerical method. Emphasis is placed on the rotation effects, including both Coriolis and centrifugal buoyancy forces, and the mass diffusion effect on the flow structure and heat transfer characteristics. Results are presented in particular for an air-water vapor system under various conditions. Predicted results show that the effects of liquid film evaporation along the porous duct walls on the mixed convection heat transfer are rather substantial. The magnitude of the evaporative latent heat transfer may be 10 times greater than that of sensible heat transfer. The predictions also demonstrate that the distributions of Nu, Sh{sub z}, and fRe are closely related to the emergence, disappearance, growth, and decay of the rotating-induced secondary vortices. Additionally, a higher Nu{sub z} is found for a rectangular duct with a larger aspect ratio ({gamma} = 2) due to the relatively stronger secondary flows.
- Sponsoring Organization:
- National Science Council, Taipei (Taiwan, Province of China)
- OSTI ID:
- 302322
- Journal Information:
- Numerical Heat Transfer. Part A, Applications, Vol. 34, Issue 7; Other Information: PBD: 27 Nov 1998
- Country of Publication:
- United States
- Language:
- English
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