So it’s highly recommended to not use iframes. I would suggest rewriting that part of your app to avoid it if you can.
Though to answer your question, there isn’t a way for the app to really do it. You can set some meta in the index html head but that’s never a guarantee it will work on all platforms.
<meta HTTP-EQUIV="PRAGMA" CONTENT="NO-CACHE">```
Another alternative, is if you can load a "new" file, it won't pull the cached file. The way to do this is like
```iframeObj.src = "http://www.example.com/page/myframe.html?random=" + (new Date()).getTime() + Math.floor(Math.random() * 1000000);``
The "?random" parameter will force a full reload since you're generating a random number that changes on every load.