Need for help for 3D airfoil computation

D.T.

I am solving three dimension Euler and NS equations for M6 airfoil problem. I have little experiment about 3D computation. I have met some trouble in Euler computation. In the head part of airfoil, the velocity of Z direction near the surface is very large; I want to know whether this phenomenon is physical? And density in first several layers grid near the airfoil surface increases very fast, which break down the computation. Could anybody give some advice to deal with such question? Best regards