Yes fans do keep flies away.
When a fan is blowing it creates the wind which makes it very difficult for flies to stay in the air flying and so since the fan will keep the flies from being able to fly properly the flies will not be able to get near you and land on you.
I use a fan to keep flies away especially when they are flying around my desk.
I've actually got a few flies right now in my house and they are trying to fly around me at my desk.
I mostly use a flyswatter to kill as many as I can so they won't be able to come back but when they do get really bad I use a fan to help keep the flies away and it does work.
The best way to stop flies from landing on you is to use a fan.
Use an electric fan and point the electric fan at you and the wind from the fan will keep the flies from being able to fly around you and they then will avoid you eventually.
I would also keep a flyswatter nearby within easy reach and try to kill the flies when they try to land on you or near you.
I try to kill most of the flies but also will use a fan when the flies are being so persistent.
Also use those fly sticky tapes that you hang up and the flies will also go to those and get stuck and die.
Fans also work great for keeping mosquitoes as well as well.
Yes you can stop mosquitoes using a fan.
Mosquitoes will stay away from you when you have a fan blowing on you because the mosquitoes will not be able to fly in the wind that the fan creates.
The wind from the fan is too powerful for the mosquitoes to fly into so they will avoid the fan and if they do fly around you the fan will blow them away.
This is how I keep mosquitoes away from me when I'm out on my back porch and want to enjoy the outdoors while mosquitoes are out.
I have a couple fans blowing around on the porch with one pointing at me and another pointing to where the mosquitoes are usually coming from.
After using a fan to keep mosquitoes away I still see the mosquitoes but they never land on me.