Hi,
Yes I use the Phoenix RC simulator. It does not works with keyboard. In my opinion you should get a radio for you. Because at last you are going to fly your models/builds with it only and not with keyboard/joystick. Secondly, you'll get habitual of flying using full controls since, keyboard gives full controls whereas in normal flying on a simulator or in real does not usually requires giving full control.
Still, just for fun or having an idea of flying untill your radio comes you can use free demo version of Real flight. It does supports keyboards/joystick. You can download it just by searching on google.