THERMAL SCIENCE

International Scientific Journal

DISCHARGE COEFFICIENT OF SMALL SONIC NOZZLES

ABSTRACT
The purpose of this investigation is to understand flow characteristics in mini/micro sonic nozzles, in order to precisely measure and control miniscule flowrates. Experimental and numerical simulation methods have been used to study critical flow Venturi nozzles. The results show that the nozzle’s size and shape influence gas flow characteristics which leading the boundary layer thickness to change, and then impact on the discharge coefficient. With the diameter of sonic nozzle throat decreasing, the discharge coefficient reduces. The maximum discharge coefficient exits in the condition of the inlet surface radius being double the throat diameter. The longer the diffuser section, the smaller the discharge coefficient becomes. Diffuser angle affects the discharge coefficient slightly.
KEYWORDS
PAPER SUBMITTED: 2013-09-30
PAPER REVISED: 2014-04-10
PAPER ACCEPTED: 2014-07-12
PUBLISHED ONLINE: 2015-01-04
DOI REFERENCE: https://doi.org/10.2298/TSCI1405505Y
CITATION EXPORT: view in browser or download as text file
THERMAL SCIENCE YEAR 2014, VOLUME 18, ISSUE 5, PAGES [1505 - 1510]
REFERENCES
  1. Wang, C., et al., Design of the Gas Source System for Sonic Nozzle Gas Flow Standard Device Based on Positive Pressure Method (in Chinese), Journal of Scientific Instrument, 6 (2012), 33, pp. 1364-1371
  2. Hu, C. C., et al., Flow Characteristics of Pyramidal Shaped Small Sonic Nozzles, Flow Measurement and Instrumentation, 22 (2011), 1, pp. 64-70
  3. Li, C. H., et al., Influence of Diffuser Angle on Discharge Coefficient of Sonic Nozzles for Flow-Rate Measurements, Flow Measurement and Instrumentation, 21 (2010), 4, pp. 531-537
  4. Wang, C., et al., Influence of Wall Roughness on Discharge Coefficient of Sonic Nozzles, Flow Measurement and Instrumentation, 35 (2014), March, pp. 55-62
  5. ISO 9300, Measurement of Gas Flow by Means of Critical Flow Venturi Nozzles, 2005
  6. Lavantee, V., et al., Investigation of Flow Fields in Small Venture-Nozzles, Proceedings, 10th International Conference on Fluid Measurement, Bahia, Brazil, 2000, F8
  7. Park, K., et al., Characteristics of Small Sonic Nozzle, Proceedings, 10th International Conference on Fluid Measurement, Bahia, Brazil, 2000, F3
  8. Li, C. H., et al., Flow Characteristics of Mini/Micro Sonic Nozzles for Micro-Flow Measurement (in Chinese), Journal of Thermal Science and Technology, 3 (2008), 7, pp. 236-239
  9. Hu, H. M., et al., Experimental Study on Critical Back-Pressure Radio of Sonic Nozzle at Low Reynolds Number (in Chinese), Journal of Scientific Instrument, 4 (2012), 23, pp. 737-742
  10. Jin, L., et al., Study on Critical Nozzle Calibration Uncertainty at Low Reynolds Number (in Chinese), Journal of Industrial Measurement, 4 (2011), 21, pp. 56-58
  11. Lim, J. M., et al., Step-Down Procedure of Sonic Nozzle Calibration at Low Reynolds Numbers, Flow Measurement and Instrumentation, 8 (2010), 21, pp. 340-346
  12. Johnson, A. N., Numerical Characterization of the Discharge Coefficient in Critical Nozzles, Pennsylvania State University, Philadelphia, Penn., USA, 2000
  13. Li, X. L., et al., Assessment of the Compressible Turbulence Model by Using the DNS Data (in Chinese), Journal of Theoretical and Applied Mechanics, 2 (2012), 44, pp. 222-229
  14. Wendt, G., Lavantee, V., Influence of Surface Roughness on the Flow Rate Behavior of Small Critical Venturi Nozzles, Flow Measurement and Instrumentation, 8 (2001), 12, pp.135-143

© 2019 Society of Thermal Engineers of Serbia. Published by the Vinča Institute of Nuclear Sciences, Belgrade, Serbia. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International licence