Některé aspekty rozpadu kapalinové stěny v tlakových vířivých sprejích

SOME ASPECTS OF DISINTEGRATION OF ANNULAR LIQUID SHEET IN PRESSURE-SWIRL ATOMIZATION

conference paper

en

In pressure-swirl (PS) atomization, the internal flow structure and the formation of a liquid film are closely linked to the quality of the resulting spray. The flow, as a subject to several disturbing sources, contain unsteadiness that can harm the atomization.In this paper, imaging is used to study discharge, near nozzle flow and primary breakup for small PS atomizer. The atomizer performance is characterised in terms of discharge coefficient, liquid sheet thickness, breakup distance, and nozzle efficiency. The breakup length according to near nozzle visualization and sheet breakup analysis wasfound much smaller than the length predicted using the inviscid model and both external and internal sources were identified as possible reasons. External flow instability sources were found by means of pressure fluctuation sensing upstream the nozzle. Phase-Doppler anemometry was used to document the mean structure of the developed spray and to characterise spray fluctuations. The findings are used to propose possible changes in the atomizer design for improvement of its performance.

Cílem této publikace je odhalit některé aspekty rozpadu kapalinové stěny v tlakových vířivých sprejích. Více info v anglickém abstraktu.

In pressure-swirl (PS) atomization, the internal flow structure and the formation of a liquid film are closely linked to the quality of the resulting spray. The flow, as a subject to several disturbing sources, contain unsteadiness that can harm the atomization.In this paper, imaging is used to study discharge, near nozzle flow and primary breakup for small PS atomizer. The atomizer performance is characterised in terms of discharge coefficient, liquid sheet thickness, breakup distance, and nozzle efficiency. The breakup length according to near nozzle visualization and sheet breakup analysis wasfound much smaller than the length predicted using the inviscid model and both external and internal sources were identified as possible reasons. External flow instability sources were found by means of pressure fluctuation sensing upstream the nozzle. Phase-Doppler anemometry was used to document the mean structure of the developed spray and to characterise spray fluctuations. The findings are used to propose possible changes in the atomizer design for improvement of its performance.

Nestability, kapalinová stěna, tlaková vířivá tryska, primární atomizace

unsteadiness, liquid sheet, pressure-swirl atomizer, primary breakup

2015

01.09.2015

Budapest

978-963-313-190-9

Conference on Modelling Fluid Flow

1–8

8