Heat transfer behavior of temperature-dependent viscoelastic non-Newtonian fluid with buoyancy effect in 2:1 rectangular duct
The fluid flows and heat-transfer behavior of non-Newtonian viscoelastic fluids has attracted special interest in recent years due to the wide application of these fluids in the chemical, pharmaceutical, petrochemical, and food industries, along with their dramatic ability to enhance heat transfer in a laminar flow through a non-circular duct. This numerical study investigates the flow characteristics and heat transfer mechanism of a viscoelastic non-Newtonian fluid in a 2:1 rectangular duct. The combined effect of temperature-dependent viscosity, buoyancy, and secondary flow caused by a second normal-stress difference is considered. The Reiner-Rivlin constitutive equation was adopted to model the viscoelastic fluid characteristics. An axially constant heat flux on the bottom wall and peripherally adiabatic boundary condition (H2) were both used. The numerical results for a polyacrylamide (Separan AP-273) solution showed a significant heat transfer enhancement compared to those of a constant property fluid, and exhibited a good consistency with experimental results for both thermal developing and thermally developed regions. In a bottom-wall-heated 2:1 rectangular duct, the main cause of the heat transfer enhancement of the viscoelastic fluid was viscoelastic-driven secondary flow, with temperature-dependent viscosity and buoyancy-induced secondary flow playing supporting roles.
- Research Organization:
- Kyungpook National Univ., Taegu (KR)
- OSTI ID:
- 20020803
- Journal Information:
- International Communications in Heat and Mass Transfer, Vol. 27, Issue 2; Other Information: PBD: Feb 2000; ISSN 0735-1933
- Country of Publication:
- United States
- Language:
- English
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