Research on Coanda Effect Appeared in Oil-Air Annular Flow through the Conical Diffuser

Abstract:

Physical model and numerical simulation model for oil-air annular flow through conical diffusers are built by Fluent, and Coanda Effect, a commonly phenomenon, appeared in this kind of oil-air annular flow field is studied, especially influences of Coanda Effect on the attachment of the liquid phase of annular flow trended to the curved wall are analyzed in detail by changing expansion angles to calculate the radial pressure distribution and pressure drop, employed numerical simulation method, in this paper. The simulation results show that the expansion angle has a great influence on the attachment of liquid phase in annular flow to the curved wall, the radial pressure gradient is an important factor of the Coanda Effect which make the liquid phase of annular flow convey near the wall, and the radial pressure gradient will decrease but the pressure drop increase when the expansion angle becomes larger. These conclusions will provide useful reference in designing pipelines conveying the two-phase annular flow in oil-air lubrication system.

• Periodical: Applied Mechanics and Materials (Volumes 668-669)
• Pages: 331-335
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.668-669.331
• Online since: October 2014
• Authors: Qi Guo Sun*, Ying Wang, Xiong Shi Wang
• Keywords: Annular Flow, Coanda Effect, Conical Diffuser

References

[1] Yalei Bai. Research and Application of Coanda Effect in the Flow Measurement [D]. Nanjing: Nanjing University of Aeronautics and Astronautics, (2007).

[2] Rosemarie M. Characteristics of a Dual-Slotted Circulation Control Wing of Low Aspect Ratio Intended for Naval Hydrodynamic Applications[J], Sci. Technol. 2000, 4: 111-123.

DOI: 10.2514/6.2004-1244

[3] Newman B G. The Deflexion of Plane Jets by Adjacent Boundaries-Coanda Effect [J]. Boundary Layer and Flow Control, Oxford, 1961, pp.232-264.

[4] Václav Tesař. Chuan-Hsiang Hung, William B Z. No-moving-part hybrid-synthetic Jet Actuator [J]. Sensors and Actuators A: Physical. 2005, 125(2): 159-169.

DOI: 10.1016/j.sna.2005.06.022

[5] Chiyu Wang. Research on Key Technologies in Fluidic Flowmeter [D]. Hangzhou: Zhejiang University, (2008).

[6] Zhihong Li. Research on the flow characteristics of the annular flow in horizon pipes of oil-air lubrication system[D]. Beijing: North China University of Technology, (2012).