<abstract xmlns="http://www.w3.org/1999/xhtml"><p>The flow around the ramp embedded in a pressurized tunnel is divided into the various zones immediately downstream of the ramp, including the cavity and the main zone of flow above the shear layer. The aeration coefficient of the flow from the lower surface (inside the cavity)(βlower) is a function of non-dimensional numbers which aerator geometry parameters such as cavity length to ramp height Lc/tr is considered as one of the most important parameters. Therefore, in the present study, OpenFOAM software and RNG k-ε turbulence model were used to simulate the flow to study the aeration effect on flow characteristics, so the range of aeration coefficient as 0%&lt;β&lt;10% for four ramps with different tr/d ratios is Applied, then by increasing the aeration coefficient in the range of 0%&lt;β&lt;16%, The dependency range of relative Cavity length Lc/tr to (β) was evaluated. In order to verify performance of the numerical model, experimental results of Manafpour test were used. The results of the research indicate that in the aeration of flow with aerator ramp, the height of ramp has more influence relative to ramp angle. Moreover the main Effectiveness of the aeration coefficient on the cavity length was limited to air percent less than 10%.</p></abstract>

The flow around the ramp embedded in a pressurized tunnel is divided into the various zones immediately downstream of the ramp, including the cavity and the main zone of flow above the shear layer. The aeration coefficient of the flow from the lower surface (inside the cavity)(βlower) is a function of non-dimensional numbers which aerator geometry parameters such as cavity length to ramp height Lc/tr is considered as one of the most important parameters. Therefore, in the present study, OpenFOAM software and RNG k-ε turbulence model were used to simulate the flow to study the aeration effect on flow characteristics, so the range of aeration coefficient as 0%<β<10% for four ramps with different tr/d ratios is Applied, then by increasing the aeration coefficient in the range of 0%<β<16%, The dependency range of relative Cavity length Lc/tr to (β) was evaluated. In order to verify performance of the numerical model, experimental results of Manafpour test were used. The results of the research indicate that in the aeration of flow with aerator ramp, the height of ramp has more influence relative to ramp angle. Moreover the main Effectiveness of the aeration coefficient on the cavity length was limited to air percent less than 10%.

Investigating the Effect of Aeration on the Flow Characteristics Around Under Pressure Tunnel Aerator Using Openfoam Open Source Software

Faculty of Engineering, Department of Civil Engineering

Journal of Applied Engineering Sciences

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

The flow around the ramp embedded in a pressurized tunnel is divided into the various zones immediately downstream of the ramp, including the cavity and the...

Investigating the Effect of Aeration on the Flow Characteristics Around Under Pressure Tunnel Aerator Using Openfoam Open Source Software

Online veröffentlicht: 25. Juli 2019

Seitenbereich: 45 - 52

Eingereicht: 22. Jan. 2019

Akzeptiert: 30. März 2019

DOI: https://doi.org/10.2478/jaes-2019-0006

Schlüsselwörter
Aerator, Pressurized tunnel, RNG K-ε Turbulence Model, OpenFOAM, Cavity length, Aeration Coefficient (β)

© 2019 Ebrahimnezhadian H et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Investigating the Effect of Aeration on the Flow Characteristics Around Under Pressure Tunnel Aerator Using Openfoam Open Source Software

Online veröffentlicht: 25. Juli 2019

Seitenbereich: 45 - 52

Eingereicht: 22. Jan. 2019

Akzeptiert: 30. März 2019

DOI: https://doi.org/10.2478/jaes-2019-0006

SchlüsselwörterAerator, Pressurized tunnel, RNG K-ε Turbulence Model, OpenFOAM, Cavity length, Aeration Coefficient (β)

© 2019 Ebrahimnezhadian H et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Schlüsselwörter
Aerator, Pressurized tunnel, RNG K-ε Turbulence Model, OpenFOAM, Cavity length, Aeration Coefficient (β)