Abonnement à la biblothèque: Guest
Portail numérique Bibliothèque numérique eBooks Revues Références et comptes rendus Collections
Interfacial Phenomena and Heat Transfer
ESCI

ISSN Imprimer: 2169-2785
ISSN En ligne: 2167-857X

Open Access

Interfacial Phenomena and Heat Transfer

DOI: 10.1615/InterfacPhenomHeatTransfer.2015012285
pages 159-183

ELECTROHYDRODYNAMIC INSTABILITY OF NON-NEWTONIAN DIELECTRIC LIQUID SHEET ISSUED INTO STREAMING DIELECTRIC GASEOUS ENVIRONMENT

Mohamed F. El-Sayed
Department of Mathematics, Faculty of Education, Ain Shams University, Heliopolis (Roxy), Cairo, Egypt; Department of Mathematics, College of Science, Qassim University, P. O. Box 6644, Buraidah 51452, Saudi Arabia
G. M. Moatimid
Department of Mathematics, Faculty of Education, Ain Shams University, Heliopolis, Roxy, Cairo, Egypt
F. M. F. Elsabaa
Department of Mathematics, Faculty of Education, Ain Shams University, Heliopolis, Roxy 11757, Cairo, Egypt
M. F. E. Amer
Department of Mathematics, Faculty of Education, Ain Shams University, Heliopolis, Roxy 11757, Cairo, Egypt

RÉSUMÉ

The linear electrohydrodynamic instability of a non-Newtonian dielectric liquid sheet issued in an inviscid gas medium of different velocity has been investigated using the Oldroyd eight-constant model. The dispersion relations between the growth rates and wave numbers of both symmetric and antisymmetric disturbances are derived. Using a new simple numerical technique, the effects of various parameters included in the analysis, namely the electric field parameter, gas to liquid velocity ratio, gas and liquid dielectric constants, time constant ratio, liquid elasticity, liquid viscosity, gas to liquid density ratio, surface tension, and liquid sheet velocity on the growth rates of symmetric and antisymmetric disturbances are studied in detail. It is found that the antisymmetric disturbances always prevail over symmetric disturbances, and the applied electric field, elasticity number, liquid velocity, gas Weber number, and gas to liquid density ratio have destabilizing effects, while the time constant ratio, surface tension, and liquid viscosity have stabilizing effects. It is also found that the gas to liquid velocity ratio and the dielectric constants have dual roles on the stability of the system (stabilizing as well as destabilizing) under certain conditions. The effects of various parameters on both the maximum growth rates and the dominant wave numbers for symmetric and antisymmetric disturbances have been discussed in detail.