Vortex

1)Create a new file and add a gradient

2)Go to Filter--Distors--Wave and apply the settings :
3)Apply Filter--Distors--Polar Coordinates.
4)Duplicate the layer and rotate it 90 degrees (Image--Rotate Canvas--Rotate 90 CCW) , and put the layer on overlay mode .
5)Go to Filter--Distors--Twirl:
6)Press CTRL+U and add colour to the image :
Final result: