The role of variable viscosity in the stability of channel flow


Pinarbasi A. , Liakopoulos A.

International Communications in Heat and Mass Transfer, cilt.22, sa.6, ss.837-847, 1995 (SCI Expanded İndekslerine Giren Dergi) identifier

  • Cilt numarası: 22 Konu: 6
  • Basım Tarihi: 1995
  • Doi Numarası: 10.1016/0735-1933(95)00072-0
  • Dergi Adı: International Communications in Heat and Mass Transfer
  • Sayfa Sayıları: ss.837-847

Özet

The stability of plane Poiseuille flow is studied for liquids exhibiting exponential viscosity-temperature dependence. In contrast to previously published studies, viscosity and temperature fluctuations are included in the formulation. Equations describing the evolution of small, two-dimensional disturbances are derived and the stability problem is formulated as an eigenvalue problem for a set of two ordinary differential equations. A Chebyshev collocation discretization method leads to a generalized matrix eigenvalue problem which is solved by the QZ algorithm. It is found that an imposed wall temperature difference, Δ T -, is always destabilizing. The instability region in the wavenumber-Reynolds number plane grows considerably as Δ T - increases. The influence of Prandtl number, temperature fluctuations and viscosity fluctuations on the flow stability/instability is small. However, their influence on the margin of stability for small wavenumbers is appreciable. © 1995.