I believe it should work since the NH-D15 has cut-outs on the heatsink on the sides to allow for larger RAM. Since the NH-D15 is a dual-tower heatsink, you have three mounting places for the fan (one in the middle, one on the side facing the front of the case, and one on the other side facing the back of the case). Since the RAM is on the side facing the front of the case, you can take the two fans and put it in the middle and on the other side. This will allow you to have a 62mm RAM clearance and the Corsair Vengeance is only 52.5mm.