Interphase interaction of near-wall liquid film with co-current gas flow inside a nozzle

Yuri Vyazov,Vyacheslav Yarygin,Igor Yarygin,Victor Prihodko,D.V Zaitsev,O.A Kabov

doi:10.1051/matecconf/20168400041

Abstract

The results of experimental study on high-velocity co-current gas flow interaction with near-wall liquid film are presented in the paper. Local parameters of near-wall liquid film are measured with the help of capacity-type probes. It is shown that co-current gas flow has strong influence on near-wall liquid film, leading to intensive wave formation, detachment of droplets from the film surface and their entrainment by the gas flow. A model for the film motion with co-current gas flow, linking together thickness and velocity of the film with value of shearing stress at gas-liquid boundary, is suggested.

Highlights

Flow of liquid in the form of thin films is widely used in various heat-andmass exchangers that involve condensation of stationary and moving vapor, absorption or desorption of gas, drying, distillation, fractioning, chemical processes, etc
Four probes were mounted around the nozzle for film thickness measurements, and two mounted probes were used for film velocity measurements
We developed the method with use of dielectric plugs, which were tightly inserted into the channel and had a groove of certain depth over the probe, filled with liquid

Summary

Introduction

Flow of liquid in the form of thin films (with thickness less than 1 mm) is widely used in various heat-andmass exchangers that involve condensation of stationary and moving vapor, absorption or desorption of gas, drying, distillation, fractioning, chemical processes, etc. Another important application of film flows is protection of walls from the high-temperature gas flow, for example, protection of liquid-propellant thrusters combustion chamber and supersonic nozzle using the near-wall fuel film. Thermocapillary instability effect and phase transformation can be significant In such phenomena condensation has a stabilizing effect, and evaporation destabilizes the flow. The results of these studies can be found for example in monographs [1, 2]

Methods

Results

Conclusion