First, as you're traveling for a few weeks, this can really hurt the chances you have. Any feelings you've built up within her will be long gone by then.

Second, since you're going away, the best you can do is hit her up again when you're back suggesting drinks. If she declines, then you know there's nothing to go after.

If she does meet you, make sure to really build attraction with her, and to make her feel amazing by being around you.

If you do it well, she will likely take contact with you the next time.

From there, I'd honestly suggest being like cocaine. Fun, interesting, and addictive, but short-lived.

Don't meet her too often. Meet her often enough to leave her crave the 'experience' with you every time she goes home and wonders when she'll see you again.

It's my strong belief that for a fwb arrangement to work, you need to be someone who she looks forward to being together with.

If you're just another boring guy, with boring thoughts, looking to do boring things - she'll have no reason to continue seeing you.