Abstract
As a kind of non-Newtonian fluid with special rheological features, the study of the breakup of power-law liquid jets has drawn more interest due to its extensive engineering applications. This paper investigated the effect of gas media confinement and asymmetry on the instability of power-law plane jets by linear instability analysis. The gas asymmetric conditions mainly result from unequal gas media thickness and aerodynamic forces on both sides of a liquid jet. The results show a limited gas space will strengthen the interaction between gas and liquid and destabilize the power-law liquid jet. Power-law fluid is easier to disintegrate into droplets in asymmetric gas medium than that in the symmetric case. The aerodynamic asymmetry destabilizes para-sinuous mode, whereas stabilizes para-varicose mode. For a large Weber number, the aerodynamic asymmetry plays a more significant role on jet instability compared with boundary asymmetry. The para-sinuous mode is always responsible for the jet breakup in the asymmetric gas media. With a larger gas density or higher liquid velocity, the aerodynamic asymmetry could dramatically promote liquid disintegration. Finally, the influence of two asymmetry distributions on the unstable range was analyzed and the critical curves were obtained to distinguish unstable regimes and stable regimes.
Highlights
The disintegration of plane liquid jets into small droplets plays a significant role on combustion efficiency in numerous applications, such as gas turbines and rocket engines
[18] According to the linear instability theory, the breakup length Lb of the jet is estimated by Heislbetz et al [23] which can be expressed by: Lb = ul ln(ηb /η0 )/sr,max where, sr, max represents the maximum growth rate gained by Equation (22), ul the jet velocity, η 0 the initial disturbance amplitude, η b the disturbance amplitude where breakup occurs and ln(η b /η 0 ) a parameter related with the amplitude of interface waves
The instability characteristics of power-law fluids on a plane jet are investigated by a linear instability analysis in the presence of gas asymmetric distributions, including the boundary asymmetry and the aerodynamic asymmetry
Summary
The disintegration of plane liquid jets into small droplets plays a significant role on combustion efficiency in numerous applications, such as gas turbines and rocket engines. The breakup mechanism of plane non-Newtonian liquid jets was investigated by Liu [10], Brenn [11], Yang [12,13] and Thompson [14] in details. Yang et al [12] investigated the instability of planar viscoelastic liquid sheets with two gas streams which were subject to unequal velocities. Deng et al [21] pointed out that the instability analysis could effectively reveal the breakup feature of power-law fluids in a comparison between experimental results and theoretical predictions. It is important to investigate the effect of gas asymmetry on the jet instability in order to understand more thoroughly the breakup mechanism of power-law fluids and provide more references for engineering applications of non-Newtonian fluids. The effects of two types of gas asymmetric distribution as well as the competition between both are investigated in detail
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
