It sounds like she may have some issue probably stemming from puppyhood, and she never learned how to play properly with other dogs, so gets confused and it turns to aggression. This can be a serious issue, for her safety, as well as that of other dogs. Have you done any obedience training with her? Can you tell what precipitates the episodes? I would definitely give her a very long walk before you get to the dog park, so she is tired when she gets there, and for now, not let her off leash while you are there, so you can be instantly aware of any untoward actions.

Is she seeming to protect you when the attacks happen? Or resource guarding? What commands does she know? Sorry so many questions!

You definitely do not need to "punish" her when she gets into fights, as that will have no good effect, and even can up having bad effect. And afterwards, when things are calm again, she won't know why, anyway. If you keep her on leash at all time, removing her from the situation and leaving the park, then have her sit, down, stay, do whatever commands she knows to get her calm again and focused on you.

This may very well be something you need an experience trainer to work with, approach and interaction with her and other dogs carefully for now, okay?