Study on properties of huge waves in churn flow

The present paper focused on huge wave's feature parameters (e. g. wave shape, wave amplitude, wave length, wave frequency, etc. ) and kinetic properties in gas-liquid two-phase churn flow in vertical pipe under different working conditions and conducted experimental study. The effects of flow parameters on feature parameters and kinetic properties of huge wave were investigated. The results indicate that the competition between gravity and shear force under different flow conditions affects the wave behavior significantly. The huge wave firstly moves downward due to the gravity till it reaches a critical amplitude for the flow reversal, which demonstrates that the flooding of the film is a characteristic of the churn flow throughout the regime and the reason makes churn flow highly disturbed. The shape of huge wave can be described by a normal-distribution function, and the wave amplitude of huge wave is larger than disturbance wave in annular flow. The amplitude and wavelength of huge wave decrease with the increase in gas flow rate but increase with the increasing liquid mass flow rate, which is similar to annular flow. At lower gas superficial velocities, the critical amplitude asymptotically approaches a constant value at greater liquid mass flow rates. The wave frequency is found to be proportional to the gas and liquid velocity.