Výzkum spreje generovaného tlakovou vířivou tryskou pomocí PIV

PIV Investigation of a Pressure-Swirl Atomizer Spray

journal article - other

en

Pressure-swirl atomizers are widely used in various combustion applications including aircraft jet engines. Spray characteristics, such as drop-size and velocity distribution have a principal influence on the combustion process. A number of studies have dealt with single-point laser diagnostic techniques, such as Phase-Doppler Anemometry, for spray measurements. An alternative approach is the use of a whole-field method – Particle Image Velocimetry (PIV). This contribution deals with investigation of spray characteristics of a spill-return pressure-swirl atomizer for a small-sized jet engine by means of PIV. The nozzle was operated on a cold test bench at atmospheric pressure and room temperature. Measurements were carried out in an axial section of the spray cone with various single-camera and stereoscopic PIV configurations. Results of our measurements provide a quantitative visualization of the spray flow fields in regimes based on the engine operating conditions. Comparison of velocity profiles obtained from the individual PIV configurations is presented and discussed. The pressure-swirl spray is recognised as an optically harsh environment for PIV due to large particle size range, high diameter–velocity correlations, strong velocity gradients and large velocity differences within an image, large variations in "seeding" concentration and out-of-plane particle movement.

Tlakové vířivé trysky jsou široce používány v různých aplikacích pro spalování včetně proudových leteckých motorů. Characteristiky spreje, jako rozložení velikosti a rychlosti kapek mají principiální dopad na spalovací proces. V tomto příspěvku je použita Particle Image Velocimetry (PIV) pro výzkum vlastností spreje generovaného tlakovou vířivou tryskou s obtokem.

Pressure-swirl atomizers are widely used in various combustion applications including aircraft jet engines. Spray characteristics, such as drop-size and velocity distribution have a principal influence on the combustion process. A number of studies have dealt with single-point laser diagnostic techniques, such as Phase-Doppler Anemometry, for spray measurements. An alternative approach is the use of a whole-field method – Particle Image Velocimetry (PIV). This contribution deals with investigation of spray characteristics of a spill-return pressure-swirl atomizer for a small-sized jet engine by means of PIV. The nozzle was operated on a cold test bench at atmospheric pressure and room temperature. Measurements were carried out in an axial section of the spray cone with various single-camera and stereoscopic PIV configurations. Results of our measurements provide a quantitative visualization of the spray flow fields in regimes based on the engine operating conditions. Comparison of velocity profiles obtained from the individual PIV configurations is presented and discussed. The pressure-swirl spray is recognised as an optically harsh environment for PIV due to large particle size range, high diameter–velocity correlations, strong velocity gradients and large velocity differences within an image, large variations in "seeding" concentration and out-of-plane particle movement.

Particle Image Velocimetry, PIV, stereoscopické PIV, atomizace, sprej, rychlostní pole

Particle Image Velocimetry, PIV, stereoscopic PIV, atomization, spray, flow field

2013

20.12.2013

Association for Engineering Mechanics

Brno

1802-1484

20 (2013)

6

459–469

11