Fyzici z Brown University aplikovali slo\u017eit\u00e9 principy dynamiky tekutin na p\u0159ekvapiv\u011b pochopiteln\u00fd probl\u00e9m: pro\u010d trv\u00e1 tak dlouho, ne\u017e posledn\u00ed kapky kapaliny odte\u010dou z n\u00e1dob. Studie publikovan\u00e1 v \u010dasopise Physics of Fluids vyu\u017e\u00edv\u00e1 dob\u0159e zn\u00e1m\u00e9 Navier-Stokesovy rovnice k p\u0159esn\u00e9 p\u0159edpov\u011bdi doby pot\u0159ebn\u00e9 k tomu, aby kapaliny s r\u016fznou viskozitou vyt\u00e9kaly vlivem gravitace. <\/p>\n
V\u00fdzkum se zrodil z ka\u017edodenn\u00edho podr\u00e1\u017ed\u011bn\u00ed. V\u00fdzkumn\u00edci Jay Tang a Thomas Dutta, kte\u0159\u00ed pracovali na samostatn\u00fdch projektech souvisej\u00edc\u00edch s chov\u00e1n\u00edm kapalin (Tang o r\u016fstu bakteri\u00ed ve vlhk\u00e9m prost\u0159ed\u00ed, Dutta o povrchov\u00e9m toku), si v\u0161imli neust\u00e1l\u00e9 frustrace z \u010dek\u00e1n\u00ed na tok visk\u00f3zn\u00edch kapalin. Dutta si vzpomn\u011bl, jak jeho babi\u010dka trvala na vylit\u00ed ka\u017ed\u00e9 posledn\u00ed kapky, a Tang \u010delil stejn\u00e9mu probl\u00e9mu, kdy\u017e \u010distil sv\u016fj litinov\u00fd wok. <\/p>\n
Kl\u00ed\u010d spo\u010d\u00edv\u00e1 ve visk\u00f3zn\u00edm re\u017eimu<\/strong> dynamiky tekutin \u2013 jak vnit\u0159n\u00ed t\u0159en\u00ed ovliv\u0148uje pohyb tekutiny. T\u00fdm pou\u017eil rovnice Navier-Stokes k modelov\u00e1n\u00ed tohoto procesu a pot\u00e9 otestoval sv\u00e9 p\u0159edpov\u011bdi nalit\u00edm tekutin, jako je voda, ml\u00e9ko, m\u00e1slo a olivov\u00fd olej, na naklon\u011bnou desku pod \u00fahlem 45 stup\u0148\u016f, na\u010dasov\u00e1n\u00edm odvodn\u011bn\u00ed, dokud nevyte\u010de 90 % tekutiny. <\/p>\n Experimenty potvrdily teoretick\u00e9 v\u00fdpo\u010dty: viskozita je dominantn\u00edm faktorem.<\/strong> Voda vytekla b\u011bhem n\u011bkolika sekund, ale studen\u00fd javorov\u00fd sirup trval hodiny. Tang, kter\u00fd z\u00e1m\u011brn\u011b nech\u00e1v\u00e1 olej na sv\u00e9m wok, aby zabr\u00e1nil reziv\u011bn\u00ed, p\u0159iznal, \u017ee podcenil \u010dekac\u00ed dobu \u2013 ide\u00e1ln\u00ed druh\u00fd sklon by byl po 15 minut\u00e1ch. <\/p>\n Nen\u00ed to jen kuchy\u0148sk\u00e1 v\u011bda. Stejn\u00e9 principy, kter\u00fdmi se \u0159\u00edd\u00ed posledn\u00ed kapka sirupu, plat\u00ed pro dynamiku bakteri\u00ed, kde proud\u011bn\u00ed tekutiny ur\u010duje chov\u00e1n\u00ed mikroorganism\u016f. Studie poskytuje v\u00fdzkumn\u00fdm pracovn\u00edk\u016fm praktick\u00e9 cvi\u010den\u00ed, ale tak\u00e9 ukazuje, jak z\u00e1kladn\u00ed fyzika je z\u00e1kladem i t\u011bch nejv\u0161edn\u011bj\u0161\u00edch aspekt\u016f ka\u017edodenn\u00edho \u017eivota. <\/p>\n \u201eTato fyzika se t\u00fdk\u00e1 cel\u00e9ho na\u0161eho z\u00e1kladn\u00edho v\u00fdzkumu… shodou okolnost\u00ed je to tak\u00e9 ka\u017edodenn\u00ed fyzika tekutin v kuchyni,\u201c vysv\u011btluje Tang. <\/p>\n<\/blockquote>\n Studie nab\u00edz\u00ed vtipnou p\u0159ipom\u00ednku, \u017ee i zd\u00e1nliv\u011b jednoduch\u00e9 jevy maj\u00ed slo\u017eit\u00e1 v\u011bdeck\u00e1 vysv\u011btlen\u00ed. Zd\u016fraz\u0148uje tak\u00e9 d\u016fle\u017eitost trp\u011blivosti, zejm\u00e9na p\u0159i manipulaci s obzvl\u00e1\u0161t\u011b visk\u00f3zn\u00edmi kapalinami.<\/p>\n","protected":false},"excerpt":{"rendered":" Fyzici z Brown University aplikovali slo\u017eit\u00e9 principy dynamiky tekutin na p\u0159ekvapiv\u011b pochopiteln\u00fd probl\u00e9m: pro\u010d trv\u00e1 tak dlouho, ne\u017e posledn\u00ed kapky kapaliny odte\u010dou z n\u00e1dob. Studie publikovan\u00e1 v \u010dasopise Physics of Fluids vyu\u017e\u00edv\u00e1 dob\u0159e zn\u00e1m\u00e9 Navier-Stokesovy rovnice k p\u0159esn\u00e9 p\u0159edpov\u011bdi doby pot\u0159ebn\u00e9 k tomu, aby kapaliny s r\u016fznou viskozitou vyt\u00e9kaly vlivem gravitace. V\u011bda o trp\u011blivosti V\u00fdzkum […]<\/p>\n","protected":false},"author":1,"featured_media":7477,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"tdm_status":"","tdm_grid_status":""},"categories":[1],"tags":[],"wpm_language_slugs":[],"amp_enabled":true,"_links":{"self":[{"href":"https:\/\/www.schooler.org.ua\/cs\/wp-json\/wp\/v2\/posts\/7478"}],"collection":[{"href":"https:\/\/www.schooler.org.ua\/cs\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.schooler.org.ua\/cs\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.schooler.org.ua\/cs\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.schooler.org.ua\/cs\/wp-json\/wp\/v2\/comments?post=7478"}],"version-history":[{"count":0,"href":"https:\/\/www.schooler.org.ua\/cs\/wp-json\/wp\/v2\/posts\/7478\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.schooler.org.ua\/cs\/wp-json\/wp\/v2\/media\/7477"}],"wp:attachment":[{"href":"https:\/\/www.schooler.org.ua\/cs\/wp-json\/wp\/v2\/media?parent=7478"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.schooler.org.ua\/cs\/wp-json\/wp\/v2\/categories?post=7478"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.schooler.org.ua\/cs\/wp-json\/wp\/v2\/tags?post=7478"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}V\u00fdsledky: Viskozita je v\u0161echno<\/h3>\n
Za kuchy\u0148sk\u00fd d\u0159ez<\/h3>\n
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