You could schedule the refresh to occur frequently - every X minutes - but there is no auto refresh just as a result of loading.
Likewise it would stink,
But you can setup a Autohotkey script that refresh's the data automatically on a virtual machine. not the cleanest way but better then waiting every 15 minutes.
but this can slow down your server having it fully automatic.
One possibility to look at the newly released Tableau extensions. In order for this to work with TS, you have to be on 2018.2 which I know is brand new, but it is an option. And if you look at this link, and follow the path, then there is an extension already built to auto-refresh. Endless possibilities with Dashboard Extensions | Tableau Software