TY - JOUR
T1 - Energetic effects on the stability of viscoelastic Dean flow
AU - Al-Mubaiyedh, U. A.
AU - Sureshkumar, R.
AU - Khomami, B.
N1 - Funding Information:
UAM would like to thank King Fahd University of Petroleum and Minerals at Dhahran, Saudi Arabia as well as the Arabian Oil Company for their support of his graduate scholarship. RS and BK gratefully acknowledge the Donors of The Petroleum Research Fund, administered by the ACS through grants 33297-G9 and 33203-AC9, respectively and NSF through grants CTS-9874813 and CTS-9612499, respectively for partial support of this research.
PY - 2000/12/25
Y1 - 2000/12/25
N2 - The influence of energetics on the linear stability of viscoelastic Dean flow of an Oldroyd-B liquid has been investigated. Our analyses show that when the temperatures of inner and outer walls are maintained at constant equal values, viscous heating does not influence the mode selection, i.e. the most dangerous disturbance is axisymmetric and stationary as in the case of isothermal Dean flow. The critical Deborah number increases with increasing Brinkman number indicating that viscous heating stabilizes the flow in this case. When the outer cylinder is kept at a higher temperature than the inner one, the most dangerous eigenmode corresponds to a non-axisymmetric disturbance with azimuthal wave number of one. For Pe4), the critical axial and temporal wave numbers for the non-isothermal flow are similar to those predicted for the isothermal case. This indicates that the critical eigenfamily is an extension of the isothermal family. For Pe>O(105), a new axisymmetric and time-dependent eigenmode with significantly different critical parameters becomes the most dangerous one. Influence of solvent viscosity and gap width on the critical parameters is also investigated. Finally, the thermoelastic mechanisms that influence the flow stability are discussed.
AB - The influence of energetics on the linear stability of viscoelastic Dean flow of an Oldroyd-B liquid has been investigated. Our analyses show that when the temperatures of inner and outer walls are maintained at constant equal values, viscous heating does not influence the mode selection, i.e. the most dangerous disturbance is axisymmetric and stationary as in the case of isothermal Dean flow. The critical Deborah number increases with increasing Brinkman number indicating that viscous heating stabilizes the flow in this case. When the outer cylinder is kept at a higher temperature than the inner one, the most dangerous eigenmode corresponds to a non-axisymmetric disturbance with azimuthal wave number of one. For Pe4), the critical axial and temporal wave numbers for the non-isothermal flow are similar to those predicted for the isothermal case. This indicates that the critical eigenfamily is an extension of the isothermal family. For Pe>O(105), a new axisymmetric and time-dependent eigenmode with significantly different critical parameters becomes the most dangerous one. Influence of solvent viscosity and gap width on the critical parameters is also investigated. Finally, the thermoelastic mechanisms that influence the flow stability are discussed.
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U2 - 10.1016/S0377-0257(00)00177-4
DO - 10.1016/S0377-0257(00)00177-4
M3 - Article
AN - SCOPUS:0034351906
SN - 0377-0257
VL - 95
SP - 277
EP - 293
JO - Journal of Non-Newtonian Fluid Mechanics
JF - Journal of Non-Newtonian Fluid Mechanics
IS - 2-3
ER -