Flow Accelerated Corrosion and Droplet Impingement Erosion in 2-Phase Steam Flow

[tazrocking]

Only looking at the horseshoe features typical of FAC and/or erosion corrosion:

I noticed that some papers described the direction of horseshoe features with the nib pointing in the direction of flow. Some OTHER papers showed the inverted direction. Which confuses me.

Is the orientation of the observed features dependent on the severity of the damage? If so, how?

Hope to learn from all of you experts! Thank you!