Introducing pre-impact air-cushioning effects into the Wagner model of impact theory
In this analysis, we consider the effects of non-quiescent initial conditions driven by pre-impact air–water interactions on the classical Wagner model of impact theory. We consider the problem of a rigid, solid impactor moving vertically towards a liquid pool. Prior to impact, viscous forces in the...
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| Format: | Journal article |
| Language: | English |
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Springer
2021
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| _version_ | 1797104986545455104 |
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| author | Moore, M |
| author_facet | Moore, M |
| author_sort | Moore, M |
| collection | OXFORD |
| description | In this analysis, we consider the effects of non-quiescent initial conditions driven by pre-impact air–water interactions on the classical Wagner model of impact theory. We consider the problem of a rigid, solid impactor moving vertically towards a liquid pool. Prior to impact, viscous forces in the air act to deform the liquid free surface, inducing a flow in the pool. These interactions are then incorporated as initial conditions in the post-impact analysis. We derive expressions for the size of the effective contact set, the leading-order pressure and force on the impactor, and the speed and thickness of the jet at its base. In all cases, we show that the effect of the pre-impact behaviour is to cushion the impactor, reducing the size of the effective contact set and, hence, the force on the impactor. Small- and large-time asymptotic solutions are derived for general power-law impactors, and we show that the effects of the air die away as the impact progresses, so that we approach the classical Wagner solution.
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| first_indexed | 2024-03-07T06:41:10Z |
| format | Journal article |
| id | oxford-uuid:f9548d26-32c1-436a-b8bd-5773cee254ad |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T06:41:10Z |
| publishDate | 2021 |
| publisher | Springer |
| record_format | dspace |
| spelling | oxford-uuid:f9548d26-32c1-436a-b8bd-5773cee254ad2022-03-27T12:57:13ZIntroducing pre-impact air-cushioning effects into the Wagner model of impact theoryJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:f9548d26-32c1-436a-b8bd-5773cee254adEnglishSymplectic ElementsSpringer2021Moore, MIn this analysis, we consider the effects of non-quiescent initial conditions driven by pre-impact air–water interactions on the classical Wagner model of impact theory. We consider the problem of a rigid, solid impactor moving vertically towards a liquid pool. Prior to impact, viscous forces in the air act to deform the liquid free surface, inducing a flow in the pool. These interactions are then incorporated as initial conditions in the post-impact analysis. We derive expressions for the size of the effective contact set, the leading-order pressure and force on the impactor, and the speed and thickness of the jet at its base. In all cases, we show that the effect of the pre-impact behaviour is to cushion the impactor, reducing the size of the effective contact set and, hence, the force on the impactor. Small- and large-time asymptotic solutions are derived for general power-law impactors, and we show that the effects of the air die away as the impact progresses, so that we approach the classical Wagner solution. |
| spellingShingle | Moore, M Introducing pre-impact air-cushioning effects into the Wagner model of impact theory |
| title | Introducing pre-impact air-cushioning effects into the Wagner model of impact theory |
| title_full | Introducing pre-impact air-cushioning effects into the Wagner model of impact theory |
| title_fullStr | Introducing pre-impact air-cushioning effects into the Wagner model of impact theory |
| title_full_unstemmed | Introducing pre-impact air-cushioning effects into the Wagner model of impact theory |
| title_short | Introducing pre-impact air-cushioning effects into the Wagner model of impact theory |
| title_sort | introducing pre impact air cushioning effects into the wagner model of impact theory |
| work_keys_str_mv | AT moorem introducingpreimpactaircushioningeffectsintothewagnermodelofimpacttheory |