Detail publikace

Effect of Geometric Factors on Spray Characteristics and Stability for Small Spill-Return Pressure-Swirl Atomizers

Originální název

Effect of Geometric Factors on Spray Characteristics and Stability for Small Spill-Return Pressure-Swirl Atomizers

Anglický název

Effect of Geometric Factors on Spray Characteristics and Stability for Small Spill-Return Pressure-Swirl Atomizers

Jazyk

en

Originální abstrakt

Pressure-swirl (PS) atomizers are popular for the simple construction and wide turn-down ratio of their spill-return (SR) versions. In this work, we experimentally investigated a small SR PS atomizer with aim to find the effect of entry port number (2, 3 and 4), swirl chamber shape (hemispheric; conical; curved convex and flat conical), SR design (axial and off-axis spill orifices) and manufacturing precision on the spray quality and stability. The characteristics (droplet size in the spray, the spray cone angle, pressure pulsations and discharge coefficient) were studied using phase-Doppler anemometry, high-speed visualization and a pressure-fluctuation sensing. The tests were provided with Jet A-1 fuel at inlet pressures of 0.5, 1.0 and 1.5 MPa and for spill/feed ratios (SFRs) of 0.4 and 0.8. The swirl chamber shape influenced the spray stability; conical chambers were more stable than others. The spray was found circumferentially heterogeneous; its uniformity improved with the increases in the swirling inlets number and the inlet pressure. Atomizers with axial spill orifice at SFR = 0 demonstrated strong spray pulsations while atomizers with the off-axis spill orifices produced a stable spray. Periodical decay of the air core was suggested as the pulsation reason. The manufacturing precision, axial symmetry and matching of the surfaces of connected parts was found important for the spray symmetry and homogeneity.

Anglický abstrakt

Pressure-swirl (PS) atomizers are popular for the simple construction and wide turn-down ratio of their spill-return (SR) versions. In this work, we experimentally investigated a small SR PS atomizer with aim to find the effect of entry port number (2, 3 and 4), swirl chamber shape (hemispheric; conical; curved convex and flat conical), SR design (axial and off-axis spill orifices) and manufacturing precision on the spray quality and stability. The characteristics (droplet size in the spray, the spray cone angle, pressure pulsations and discharge coefficient) were studied using phase-Doppler anemometry, high-speed visualization and a pressure-fluctuation sensing. The tests were provided with Jet A-1 fuel at inlet pressures of 0.5, 1.0 and 1.5 MPa and for spill/feed ratios (SFRs) of 0.4 and 0.8. The swirl chamber shape influenced the spray stability; conical chambers were more stable than others. The spray was found circumferentially heterogeneous; its uniformity improved with the increases in the swirling inlets number and the inlet pressure. Atomizers with axial spill orifice at SFR = 0 demonstrated strong spray pulsations while atomizers with the off-axis spill orifices produced a stable spray. Periodical decay of the air core was suggested as the pulsation reason. The manufacturing precision, axial symmetry and matching of the surfaces of connected parts was found important for the spray symmetry and homogeneity.

BibTex


@inproceedings{BUT128577,
  author="Jan {Jedelský} and Milan {Malý} and Lada {Janáčková} and Miroslav {Jícha}",
  title="Effect of Geometric Factors on Spray Characteristics and Stability for Small Spill-Return Pressure-Swirl Atomizers",
  annote="Pressure-swirl (PS) atomizers are popular for the simple construction and wide turn-down ratio of their spill-return (SR) versions. In this work, we experimentally investigated a small SR PS atomizer with aim to find the effect of entry port number (2, 3 and 4), swirl chamber shape (hemispheric; conical; curved convex and flat conical), SR design (axial and off-axis spill orifices) and manufacturing precision on the spray quality and stability.
The characteristics (droplet size in the spray, the spray cone angle, pressure pulsations and discharge coefficient) were studied using phase-Doppler anemometry, high-speed visualization and a pressure-fluctuation sensing. The tests were provided with Jet A-1 fuel at inlet pressures of 0.5, 1.0 and 1.5 MPa and for spill/feed ratios (SFRs) of 0.4 and 0.8. 
The swirl chamber shape influenced the spray stability; conical chambers were more stable than others. The spray was found circumferentially heterogeneous; its uniformity improved with the increases in the swirling inlets number and the inlet pressure. Atomizers with axial spill orifice at SFR = 0 demonstrated strong spray pulsations while atomizers with the off-axis spill orifices produced a stable spray. Periodical decay of the air core was suggested as the pulsation reason. The manufacturing precision, axial symmetry and matching of the surfaces of connected parts was found important for the spray symmetry and homogeneity.
",
  booktitle="27th European Conference on Liquid Atomization and Spray Systems",
  chapter="128577",
  howpublished="electronic, physical medium",
  year="2016",
  month="september",
  pages="1--12",
  type="conference paper"
}