dorsal/arxiv
View SchemaAn Elementary Treatment of the Reverse Sprinkler
| Authors | Alejandro Jenkins |
|---|---|
| Categories | |
| ArXiv ID | physics/0312087 |
| URL | https://arxiv.org/abs/physics/0312087 |
| DOI | 10.1119/1.1761063 |
| Journal | Am. J. Phys. 72 (2004) 1276-1282 |
Abstract
We discuss the reverse sprinkler problem: How does a sprinkler turn when submerged and made to suck in water? We propose a solution that requires only a knowledge of mechanics and fluid dynamics at the introductory university level. We argue that as the flow of water starts, the sprinkler briefly experiences a torque that would make it turn toward the incoming water, while as the flow of water ceases it briefly experiences a torque in the opposite direction. No torque is expected when water is flowing steadily into it unless dissipative effects, such as viscosity, are considered. Dissipative effects result in a small torque that would cause the sprinkler arm to accelerate toward the steadily incoming water. Our conclusions are discussed in light of an analysis of forces, conservation of angular momentum, and the experimental results reported by others. We review the conflicting published treatments of this problem, some of which have been incorrect and many of which have introduced complications that obscure the basic physics involved.
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"abstract": "We discuss the reverse sprinkler problem: How does a sprinkler turn when\nsubmerged and made to suck in water? We propose a solution that requires only a\nknowledge of mechanics and fluid dynamics at the introductory university level.\nWe argue that as the flow of water starts, the sprinkler briefly experiences a\ntorque that would make it turn toward the incoming water, while as the flow of\nwater ceases it briefly experiences a torque in the opposite direction. No\ntorque is expected when water is flowing steadily into it unless dissipative\neffects, such as viscosity, are considered. Dissipative effects result in a\nsmall torque that would cause the sprinkler arm to accelerate toward the\nsteadily incoming water. Our conclusions are discussed in light of an analysis\nof forces, conservation of angular momentum, and the experimental results\nreported by others. We review the conflicting published treatments of this\nproblem, some of which have been incorrect and many of which have introduced\ncomplications that obscure the basic physics involved.",
"arxiv_id": "physics/0312087",
"authors": [
"Alejandro Jenkins"
],
"categories": [
"physics.flu-dyn",
"physics.ed-ph",
"physics.hist-ph"
],
"doi": "10.1119/1.1761063",
"journal_ref": "Am. J. Phys. 72 (2004) 1276-1282",
"title": "An Elementary Treatment of the Reverse Sprinkler",
"url": "https://arxiv.org/abs/physics/0312087"
},
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