On the instability of liquid jet and liquid curtain
Abstract
The spatial instability of liquid jets and liquid curtains is investigated by using linear theory. For the case of a viscous liquid jet into an inviscid ambient gas, a unified theory is developed. It is found that the existing theories, including Rayleigh, Keller, Taylor, and Chandrasekhar's modes, are only special cases of the unified theory. Thus, this new theory would fill up the vacuum and bridge the gaps between the existing theories and be used to verify the validity range of the existing modes. The different effects of various jet flow parameters on jet stability were analysed from the computational results based on this unified theory to investigate the mechanism of jet breakup. The absolute instability of the viscous liquid jet in inviscid gas is studied, and the critical Weber number, above which the jet is absolutely unstable, is determined as a function of Reynolds number and gas to liquid density ratio. This unified theory is extended to the more general case of a viscous liquid jet injected into a swirling ambient gas, it is found that the gas swirling is a stabilizing factor while the gas density may have dual effects on the jet stability. The instability analysis of a liquid curtain in a vacuum is extended to the case of a viscous liquied curtain in an ambient gas. The participation of the ambient gas is found to change the stability of the liquid curtain both quantitatively and qualitatively.
- Publication:
-
Ph.D. Thesis
- Pub Date:
- 1990
- Bibcode:
- 1990PhDT........33L
- Keywords:
-
- Curtains;
- Flow Stability;
- Fluid Jets;
- Inviscid Flow;
- Jet Flow;
- Liquid Flow;
- Flow Characteristics;
- Gas Density;
- Reynolds Number;
- Theories;
- Fluid Mechanics and Heat Transfer