How can I divert wind which is flowing parallel to the wall into the house?
I think the ideal solution would be to get casement windows. If the wind blows in both direction (at different times) you could go with a set of casements and open the applicable one:



Barring that, I think you need to rig up something that works the same say...perhaps a sheet metal 'vent hood' mounted at an angle. Or even perhaps just a piece of plywood.