{"id":2010296,"date":"2026-06-25T00:00:00","date_gmt":"2026-06-24T21:00:00","guid":{"rendered":"https:\/\/analyse.optim.biz\/?p=2010296"},"modified":"2026-06-25T00:00:00","modified_gmt":"2026-06-24T21:00:00","slug":"how-to-quickly-cool-a-hot-car-using-just-your-arms-and-some-fluid-dynamics","status":"publish","type":"post","link":"https:\/\/analyse.optim.biz\/?p=2010296","title":{"rendered":"How to quickly cool a hot car using just your arms and some fluid dynamics"},"content":{"rendered":"
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Hannah Fry is a maths professor, science writer and broadcaster, and has reshared a \u2013 quite literally \u2013 cool tip on how to quickly lower the temperature inside your car<\/a> using nothing more than a few embarrassing movements and a rear window.<\/p>\n

No, she\u2019s not advocating you go all Hitchcock and start spying on your neighbours to distract you from the raging hellscape outside, but instead she\u2019s explaining how the power of air flow can quickly refresh your car\u2019s cabin.<\/p>\n<\/div>\n

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\u201cThere\u2019s a fluid dynamics trick you can use to quickly cool your car down,\u201d the good professor said in an Insta video. And she\u2019d know, because she\u2019s got a PHD in fluid dynamics.<\/p>\n

First, she explains, you have to open the rear window on the opposite side of the driver\u2019s door \u2013 handy if you\u2019ve got four doors, admittedly not so handy if you\u2019re in, say, a Lincoln Continental MkV coupe, but we digress \u2013 and then do the embarrassing thing.<\/p>\n<\/div>\n

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\u201cYou do look like a bit of an idiot,\u201d she said, \u201cbut just very quickly open and close the driver\u2019s door.<\/p>\n

\u201cThe reason why it works is that when you open and close the door, especially if you do it quickly, the door \u2013 as it\u2019s moving outwards \u2013 it sweeps out all the air that\u2019s in its way creating this area of low pressure.<\/p>\n<\/div>\n

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\u201cAnd then that sets up something called \u2018bulk flow\u2019, which is where all of the hot, sweaty, horrible air inside the car is drawn outwards. And the only way to refill it is with nice, fresh, easy air from over [the other] side.<\/p>\n

Nine of the best car interiors of the 21st Century<\/a><\/p>\n

\u201cIt only takes about two or three goes and suddenly it\u2019s beautifully temperate.\u201d<\/p>\n

Let\u2019s be honest, you\u2019ve done more embarrassing things in your car.<\/p>\n<\/div>\n

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A post shared by Hannah Fry (@fryrsquared)<\/a><\/p>\n<\/div>\n<\/blockquote>\n<\/div>\n","protected":false},"excerpt":{"rendered":"

Hannah Fry is a maths professor, science writer and broadcaster, and has reshared a \u2013 quite literally \u2013 cool tip on how to quickly lower the temperature inside your car using nothing more than a few embarrassing movements and a rear window. No, she\u2019s not advocating you go all Hitchcock and start spying on your […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[226,237],"class_list":["post-2010296","post","type-post","status-publish","format-standard","hentry","category-uncategorized","tag-crawlmanager","tag-topgear-com"],"_links":{"self":[{"href":"https:\/\/analyse.optim.biz\/index.php?rest_route=\/wp\/v2\/posts\/2010296","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/analyse.optim.biz\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/analyse.optim.biz\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/analyse.optim.biz\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/analyse.optim.biz\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2010296"}],"version-history":[{"count":0,"href":"https:\/\/analyse.optim.biz\/index.php?rest_route=\/wp\/v2\/posts\/2010296\/revisions"}],"wp:attachment":[{"href":"https:\/\/analyse.optim.biz\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2010296"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/analyse.optim.biz\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2010296"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/analyse.optim.biz\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2010296"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}