{"id":4665,"date":"2018-03-29T03:06:00","date_gmt":"2018-03-29T03:06:00","guid":{"rendered":"http:\/\/thales.mit.edu\/bush\/?p=4665"},"modified":"2021-04-15T02:13:37","modified_gmt":"2021-04-15T02:13:37","slug":"walker-pillar-interactions-from-scattering-to-the-logarithmic-spiral","status":"publish","type":"post","link":"https:\/\/thales.mit.edu\/bush\/index.php\/2018\/03\/29\/walker-pillar-interactions-from-scattering-to-the-logarithmic-spiral\/","title":{"rendered":"Walker-pillar interactions"},"content":{"rendered":"\n
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A walking droplet interacts with a submerged pillar. Wave-mediated forces induce a lift force that causes the droplet to follow a logarithmic spiral.<\/figcaption><\/figure><\/div>\n\n\n\n

Millimetric droplets may walk across the surface of a vibrating fluid bath, propelled forward by their own guiding or \u201cpilot\u201d wave field. We here consider the interaction of such walking droplets with a submerged circular pillar. While simple scattering events are the norm, as the waves become more pronounced, the drop departs the pillar along a path corresponding to a logarithmic spiral. The system behavior is explored both experimentally and theoretically, using a reduced numerical model in which the pillar is simply treated as a region of decreased wave speed. A trajectory equation valid in the limit of weak droplet acceleration is used to infer an effective force due to the presence of the pillar, which is found to be a lift force proportional to the product of the drop\u2019s walking speed and its instantaneous angular speed around the post. This system presents a macroscopic example of pilot-wave-mediated forces giving rise to apparent action at a distance.<\/p>\n\n\n\n

See paper: Harris, D.M., Brun, P.-T., Damiano, A., Faria, L.M. and Bush, J.W.M. (2018)<\/a><\/p>\n<\/div><\/div>\n","protected":false},"excerpt":{"rendered":"","protected":false},"author":5,"featured_media":4667,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[15,3],"tags":[],"class_list":["post-4665","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-hydrodynamic-quantum-analogues","category-pilot-wave-hydrodynamics","entry"],"yoast_head":"\nWalker-pillar interactions - John W. M. Bush<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/thales.mit.edu\/bush\/index.php\/2018\/03\/29\/walker-pillar-interactions-from-scattering-to-the-logarithmic-spiral\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Walker-pillar interactions - John W. M. Bush\" \/>\n<meta property=\"og:url\" content=\"https:\/\/thales.mit.edu\/bush\/index.php\/2018\/03\/29\/walker-pillar-interactions-from-scattering-to-the-logarithmic-spiral\/\" \/>\n<meta property=\"og:site_name\" content=\"John W. M. 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