<abstract xmlns="http://www.w3.org/1999/xhtml"><p>Induced air pressure and resulting free surface profile due to air cushioning layer is studied. The study is mainly focused on 2D blunt circular bodies with constant downward speed. The problem is first solved for the air flow between the body and the free surface of the water. Then the results are employed to solve the problem for the water problem, numerically. Both air and water problem are assumed to be governed by Laplace potential equation. Depending on the induced pressure and velocity of the escaping air flow from cushioning layer, compressibility of the air is also included in the modeling. Gravitational acceleration is also included in the model. An iterative boundary element method is used for numerical solution of both air and water problems. Instantaneous pressure distribution and free surface profile are evaluated for different bodies. The results of calculation for large blunt bodies show that inviscid potential method can fairly approximate the problem for large blunt bodies. Additionally, the behavior of the air pressure for the very blunt body is impulsive and the magnitude of the peak pressure is in order of impact pressure of water entry. The obtained results are compared with analytical method. The comparison shows that as the bluntness of a body increases, the better agreement is concluded.</p></abstract>

Induced air pressure and resulting free surface profile due to air cushioning layer is studied. The study is mainly focused on 2D blunt circular bodies with constant downward speed. The problem is first solved for the air flow between the body and the free surface of the water. Then the results are employed to solve the problem for the water problem, numerically. Both air and water problem are assumed to be governed by Laplace potential equation. Depending on the induced pressure and velocity of the escaping air flow from cushioning layer, compressibility of the air is also included in the modeling. Gravitational acceleration is also included in the model. An iterative boundary element method is used for numerical solution of both air and water problems. Instantaneous pressure distribution and free surface profile are evaluated for different bodies. The results of calculation for large blunt bodies show that inviscid potential method can fairly approximate the problem for large blunt bodies. Additionally, the behavior of the air pressure for the very blunt body is impulsive and the magnitude of the peak pressure is in order of impact pressure of water entry. The obtained results are compared with analytical method. The comparison shows that as the bluntness of a body increases, the better agreement is concluded.

Numerical Simulation of Cushioning Problem for Blunt Bodies Using Boundary Element Method

Polish Maritime Research

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Induced air pressure and resulting free surface profile due to air cushioning layer is studied. The study is mainly focused on 2D blunt circular bodies with...

Numerical Simulation of Cushioning Problem for Blunt Bodies Using Boundary Element Method

Publié en ligne: 07 juin 2018

Pages: 85 - 93

DOI: https://doi.org/10.2478/pomr-2018-0028

Mots clés
Air cushion, compressible potential flow, water entry, slamming

© 2018 Mojtaba Barjasteh et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Numerical Simulation of Cushioning Problem for Blunt Bodies Using Boundary Element Method

Publié en ligne: 07 juin 2018

Pages: 85 - 93

DOI: https://doi.org/10.2478/pomr-2018-0028

Mots clésAir cushion, compressible potential flow, water entry, slamming

© 2018 Mojtaba Barjasteh et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Mots clés
Air cushion, compressible potential flow, water entry, slamming