Temporal instability of gas jets injected in viscous liquids to three-dimensional disturbances

A temporal linear stability analysis of an inviscid incompressible gas jet injected into a co-flowing viscous liquid was conducted to study the growth of small three-dimensional disturbances that lead to the break-up of the gas jet. The primary flow parameter that governed the growth of the disturbances was the gas Weber number. At small Weber numbers, only the two-dimensional varicose disturbances were unstable; at high Weber numbers, three-dimensional disturbances became unstable with growth rates comparable to the sinuous and varicose disturbances. The phase velocity of the disturbances in the gas jet was small, on the order of the co-flowing liquid velocity.