Ok, this time we will create a simple effect like this.
Create a material in the Post Process domain.
As a texture pick any noise texture. There are some in the engine. Tiling noise would work best.
The material is all about the way we sample the noise texture. First we move our UV's (0.0, 0.0) point to the center of the screen by subtracting 0.5. The next step is to normalize our UVs, so we would only sample pixels that are on an unit circle. This creates lines that go from the sides to the center of our view. Next part is to cut out a gradient in the effect, so it only appears near the edges. The last step is to interpolate between the Scene Color and the Speed Lines color.
After you have the material you just need to add a Post Process Component to your character's blueprint and add this code. This is just a quick example on how you could use the effect. There are better ways. Remember - never hardcode any values!
This code basically interpolates between values 0-1 for the effect weight and 90-120 for FOV based on character's movement speed. Using higher FOV value would make the effect look way more awesome.