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Linear stability analysis of mixed convection flow in a horizontal channel filled with nanofluids
Author(s) -
Bammou Lahcen,
Souhar Khalid,
Alami Samy,
Feddaoui M'Barek,
Le Guer Yves
Publication year - 2020
Publication title -
heat transfer
Language(s) - English
Resource type - Journals
eISSN - 2688-4542
pISSN - 2688-4534
DOI - 10.1002/htj.21721
Subject(s) - nanofluid , hagen–poiseuille equation , mechanics , rayleigh number , linear stability , flow (mathematics) , materials science , buoyancy , instability , mathematics , convection , physics , heat transfer , natural convection
Abstract The convective instability driven by buoyancy in the Poiseuille–Rayleigh–Bénard flow through two infinite parallel horizontal plates filled with nanofluids is investigated using linear stability analysis. We considered water‐based nanofluids with different volume fractions of aluminum ( A l 2 O 3 ) and silver ( A g ) nanoparticles. A spectral collocation method founded on Chebyshev polynomials is implemented and the obtained algebraic eigenvalue problem is solved. In this study, we have numerically determined the critical Rayleigh number of the onset of longitudinal and transversal rolls and the results are represented in the form of marginal stability curves. Critical wave numbers that describe the size of convective cells in the flow are also presented, analyzed, and compared with those of the Poiseuille–Rayleigh–Bénard flow without nanoparticles. The effects of the type and nanoparticle volume fractions on the onset of both longitudinal and transversal rolls are investigated.