Natural convection of nanofluids in solar energy collectors based on a two-phase lattice Boltzmann model
| Autor: | Chunyang Li, Dongtai Han, Cong Qi, Keao Li |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Convection
Materials science Natural convection business.industry Non-equilibrium thermodynamics Laminar flow 02 engineering and technology Mechanics Rayleigh number 021001 nanoscience & nanotechnology Condensed Matter Physics Solar energy 01 natural sciences 010406 physical chemistry 0104 chemical sciences Physics::Fluid Dynamics Nanofluid Heat transfer Physical and Theoretical Chemistry 0210 nano-technology business |
| Zdroj: | Journal of Thermal Analysis and Calorimetry. 147:2417-2438 |
| ISSN: | 1588-2926 1388-6150 |
| DOI: | 10.1007/s10973-021-10668-8 |
| Popis: | In order to improve the photothermal conversion efficiency of solar energy collectors, the laminar convection of nanofluids in five types of solar energy collectors was numerically studied with a two-phase lattice Boltzmann model. In the current simulation, Cu–water nanofluids (volume fraction φ = 0.3%) were chosen. The equilibrium distribution function with D2Q9 model and the boundary conditions of nonequilibrium extrapolation scheme were applied to establish the lattice Boltzmann model. The effects of different Rayleigh numbers (Ra = 104–106), structures (rectangle cavity, trapezoid cavity and parallelogram cavity) and aspect ratios (A = 2:1, 4:3 and 1:1) of solar energy collectors on the heat transfer were considered. The temperature distribution, streamline and entropy generation of nanofluids in the solar energy collectors were analyzed. Results demonstrated that the increase in Rayleigh number heightens the heat convection of nanofluids. The trapezoid cavity and parallelogram have a special structure, which will form a flow dead zone, weaken the heat transfer effect and determine the position of maximum entropy generation. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full text from SpringerLink