Numerical simulation of a vectored axisymmetric nozzle

Assessment of different turbulence models in simulating axisymmetric flow in suddenly expanded nozzles

International Journal of Engineering & Technology ◽

10.14419/ijet.v7i3.29.18804 ◽

2018 ◽

Vol 7 (3.29) ◽

pp. 243

Author(s):

Sher Afghan Khan ◽

Mir Owais Ali ◽

Miah Mohammed Riyadh ◽

Zahid Hossen ◽

Nafis Mahdi Arefin

Keyword(s):

Numerical Simulation ◽

Numerical Analysis ◽

Mach Number ◽

Numerical Simulations ◽

Axisymmetric Flow ◽

Turbulence Models ◽

Experimental Results ◽

Nozzle Flow ◽

Axisymmetric Nozzle ◽

Good Agreement

A numerical simulation was carried out to compare various turbulence models simulating axisymmetric nozzle flow past suddenly expanded ducts. The simulations were done for L/D = 10. The convergent-divergent nozzle has been modeled and simulated using the turbulence models: The Standard k-ε model, The Standard k-ω model and The SST k-ω model. Numerical simulations were done for Mach numbers 1.87, 2.2, and 2.58 and the nozzles were operated for NPRs in the range from 3 to 11. From the numerical analysis it is apparent that for a given Mach number and effect of NPR will result in maximum gain or loss of pressure. Numerical results are in good agreement with the experimental results.

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Bubble Tracking Simulation of Cavitating Flow in an Atomization Nozzle

Volume 1: Fora, Parts A and B ◽

10.1115/fedsm2002-31018 ◽

2002 ◽

Cited By ~ 2

Author(s):

Akira Sou ◽

Shinichi Nitta ◽

Tsuyoshi Nakajima

Keyword(s):

Numerical Simulation ◽

Pressure Distribution ◽

Cavitation Bubble ◽

Injection Pressure ◽

Cavitating Flow ◽

Experimental Result ◽

Axisymmetric Nozzle ◽

Cloud Cavitation ◽

Vena Contracta ◽

Bubble Clouds

Numerical simulation of transient cavitating flow in a axisymmetric nozzle was conducted in order to investigate the detailed motion of cavitation bubble clouds which may be dominant to atomization of a liquid jet. Two-way coupled bubble tracking technique was assigned in the present study to predict the unsteady cloud cavitation phenomena. Large Eddy Simulation (LES) was used to predict turbulent flow. Calculated pressure distribution and injection pressure were compared with measured ones. Then, calculated motion of cavitation bubble clouds was carefully investigated to understand the cavitation phenomena in a nozzle. As a result, the following conclusions were obtained: (1) Calculated result of pressure distribution along the wall, the relation between injection pressure vs. flow rate, and bubble distribution agreed with existing experimental result. (2) Cavitation bubble clouds were periodically shed from the tail of vena contracta, which usually formed by the coalescence of a few small bubble clouds. (3) Collapse of cavitation bubbles due to the re-entrant jet was observed in the numerical simulation.

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