Influence of water injection on broadband noise and hydrodynamic performance for a NACA66 (MOD) hydrofoil under cloud cavitation condition

A method of water injection to flow field using distributed holes on the suction surface of hydrofoil is presented in this article to control cavitation flow. Modified renormalization group k–ε turbulence model is coupled with full-cavitation model to calculate periodical cavitation patterns and the dynamic characteristics of the NACA66(MOD) hydrofoil. Water injection is found to be highly effective for cavitation suppression. The cavitation suppression effect of distributed regulation of jet holes and porosities along three-dimensional spanwise hydrofoil is also investigated. The appropriate porosities of single row spanwise jet holes and optimal jet position of double row jet holes are revealed for both cavitation suppression and good hydrodynamic performance. Double row jet holes setting in forward trapezoidal arrangement shows great potential for cavitation suppression and hydrodynamic performance. This research provides a method of water injection to flow field to actively control cavitation, which will facilitate development of engineering designs.

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Simulations of rocket launch noise suppression with water injection from impingement pad

International Journal of Aeroacoustics ◽

10.1177/1475472x20930653 ◽

2020 ◽

Vol 19 (3-5) ◽

pp. 207-239

Author(s):

Saman Salehian ◽

Reda R Mankbadi

Keyword(s):

Large Eddy Simulation ◽

Fluid Model ◽

Water Injection ◽

Broadband Noise ◽

Computational Domain ◽

Two Phase ◽

Effect Of Water ◽

Eddy Simulation ◽

Impingement Plate ◽

Large Eddy

The focus of this work is on understanding the effect of water injection from the launch pad on the noise generated during rocket’s lift-off. To simplify the problem, we consider a supersonic jet impinging on a flat plate with water injection from the impingement plate. The Volume of Fluid model is adopted in this work to simulate the two-phase flow. A Hybrid Large Eddy Simulation – Unsteady Reynolds Averaged Simulation approach is employed to model turbulence, wherein Unsteady Reynolds Averaged Simulation is used near the walls, and Large Eddy Simulation is used elsewhere in the computational domain. The numerical issues associated with simulating the noise of two-phase supersonic flow are addressed. The pressure fluctuations on the impingement plate obtained from numerical simulations agree well with the experimental data. Furthermore, the predicted effect of water injection on the far-field broadband noise is consistent with that of the experiment. The possible mechanisms for noise reduction by water injection are discussed.

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Computational Study on Influence of Water Injection Angle to Aluminum/Water Reaction Motor

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.248.539 ◽

2012 ◽

Vol 248 ◽

pp. 539-544

Author(s):

Zheng He ◽

Xuan Gu ◽

Ye Gao

Keyword(s):

Computational Study ◽

Aluminum Particle ◽

Specific Impulse ◽

Water Injection ◽

Water Droplets ◽

Aluminum Particles ◽

Injection Angle ◽

Influence Of Water ◽

Afterburning Chamber ◽

Multi Phase

In Aluminum/Water Reaction Motor chamber, water injection angle plays an important role on mixture of aluminum particle fuel and water droplets and can affect motor performance further. On the basis of FLUENT software and taking phase transition and reaction between water droplets and aluminum particles into account, numerically simulated cases of different water injection angles by Particle Stochastic Trajectory Model. Computed total evaporation rate of water droplets, reaction rate of aluminum particles and specific impulse for the motor. Furthermore judged injection angle effect from these parameters. By comparison and analysis, it is found that hybrid injection case could get best multi-phase mixture effect and specific impulse performance for the motor. Namely axial injection angle with 45°in the main chamber and tangential injection angle with 60°in the afterburning chamber is the best case. The conclusion could provide a new idea for motor working process design.

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Influence of Water Injection on Performance and Emissions of a Direct-Injection Hydrogen Research Engine

10.4271/2008-01-2377 ◽

2008 ◽

Cited By ~ 21

Author(s):

Abhijeet M. Nande ◽

Thomas Wallner ◽

Jeffrey Naber

Keyword(s):

Direct Injection ◽

Water Injection ◽

Performance And Emissions ◽

Influence Of Water

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Experimental Investigation of the Influence of Water Injection on Acoustic Properties of the Exhaust System of a Gas Turbine Combustion Test Rig

Volume 2: Combustion, Fuels and Emissions, Parts A and B ◽

10.1115/gt2011-46366 ◽

2011 ◽

Author(s):

Martin Schmid ◽

Natalie Trott ◽

Robert Kathan ◽

Dan Fanaca ◽

Thomas Sattelmayer

Keyword(s):

Gas Turbine ◽

Gas Turbines ◽

Droplet Diameter ◽

Water Injection ◽

Exhaust System ◽

Acoustic Properties ◽

Sonic Velocity ◽

Test Rig ◽

Stability Behavior ◽

Influence Of Water

It is a known phenomenon that single can combustion test rigs and gas turbines have a different stability behavior. Real gas turbines are often more stable than their test rigs. One main difference between test rigs and real engines is the injection of cooling water into the test rigs to reduce the temperature of the exhaust gas and thus to protect the exhaust valve. A literature survey showed that the presence of a two phase flow can drastically reduce the sonic velocity and consequently change the acoustic properties of a system. The aim of this project is to study the influence of water injection on the acoustic properties of a test rig representing the exhaust system of a gas turbine. The experimental results clearly show that the sonic velocity does not change in the present test rig because the droplets are too big to follow the acoustic fluctuations. The critical dimension-less number in this context is the Stokes number, which is mainly determined by the droplet diameter and the acoustic frequency. Furthermore, the experimental results point out that the injected water increases the acoustic damping. It can be concluded from this study that the influence of water injection on the acoustic properties and therefore on the stability behavior is very sensitive to the injection conditions, especially the droplet diameter.

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