Lattice Boltzmann simulation of nanofluid natural/mixed convection heat transfer

• Main Authors: Chun-KaiChang, 張駿愷
• Other Authors: Cha’o-Kuang Chen
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/28913572604744787599

碩士 === 國立成功大學 === 機械工程學系碩博士班 === 100 === In the present study, mathematical modeling is performed to simulate two-dimensional incompressible natural and mix convection of nanofluids in a vertical square enclosure and channel using the lattice Boltzmann method(LBM).Consider the effects of different concentration of nanofluids (0%, 2%, 4%), Rayleight number and Richardson number to averaged Nusselt number, and Consider the effects of putting a rectangle hole in vertical channel with different ratio of height and length to Nusselt number, averaged Nusselt number, and temperature field. The inlet velocity is chosen appropriately, so as to ensure the reasonable adaptation of fluid field and to avoid un-physical compressible effect. Numerical results show that the averaged Nusselt number of nanofluids can be higher than pure water. Increasing the nanoparticle volume fraction will enhance the averaged Nusselt number. The averaged Nusselt number also increases by the temperature change caused by the increase of the Rayleigh number, the characteristic velocity change caused by Richardson number reduction. In the presence of significantly effects of the ratio of height and length of the rectangle hole to velocity field and vortex shape, and the averaged Nusselt number will decrease when the rectangle hole increased.