Experimental study of submillimeter droplets dynamics and breakup in continuous supersonic flow terminated by shock wave

Oleg Gobyzov,Yuriy Lozhkin,Dmitriy Markovich,Mikhail Ryabov,P Dančová,M Veselý

doi:10.1051/epjconf/201611402031

Oleg Gobyzov, Yuriy Lozhkin + Show 4 more

Open Access

https://doi.org/10.1051/epjconf/201611402031

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Abstract

The present paper reports an application of optical methods, namely PIV, background-oriented-schlieren (BOS) and high-magnification imaging with background illumination to study of dynamics and breakup of 10-100 μm size droplets in continuous supersonic flow terminated by a normal shock wave. Flow diagnostics was performed by means of BOS and PIV. Shadow photography allowed to specify velocity ranges for different droplet sizes and to visualize droplets dynamics and breakup modes. Features of the experimental setup and certain details of implemented measurement system are considered. Results of velocity measurements and droplets behavior, including deformation and breakup, are presented and analysis of experimental conditions and dimensionless parameters affecting the droplets behavior is performed. Distinctive features of deformation and breakup processes of submillimeter scale droplets are revealed.

Highlights

Investigation of liquid drops deformation and breakup in high-speed flows has many scientific and technological applications: combustion of liquid fuels, erosion of steam turbine blades, cold spray processing and others
The present paper reports an application of optical methods, namely particle image velocimetry (PIV), background-oriented-schlieren (BOS) and high-magnification imaging with background illumination to study of dynamics and breakup of 10100 ȝm size droplets in continuous supersonic flow terminated by a normal shock wave
Through the last several decades a large number of experimental works, aimed on identification of droplets atomization regimes, systematization of amassed information and revealing of influencing parameters were performed. In this investigations it was shown that atomization of liquid droplets due to aerodynamic forces is a complex process that involves different physical mechanisms depending on the experimental conditions

Summary

Introduction

Investigation of liquid drops deformation and breakup in high-speed flows has many scientific and technological applications: combustion of liquid fuels, erosion of steam turbine blades, cold spray processing and others. Through the last several decades a large number of experimental works, aimed on identification of droplets atomization regimes, systematization of amassed information and revealing of influencing parameters were performed. In this investigations it was shown that atomization of liquid droplets due to aerodynamic forces is a complex process that involves different physical mechanisms depending on the experimental conditions. In the present work several optical measurement methods, among which are particle image velocimetry (PIV), background-oriented schlieren (BOS) and highmagnification imaging with background illumination (shadow photography, SP) were applied to study dynamics and breakup of submillimeter droplets in continuous supersonic flow with normal shock wave. Results of flow and droplets velocity measurements and visualization of particle behaviour, including deformation and breakup, are presented

Setup and measurement techniques

Flow diagnostics a b

Droplets deformation and breakup

Conclusions