3D lungwave case file fix

Author: mrodrig6

examples/3D_lungwave/case.py

@@ -181,7 +181,7 @@
             "patch_icpp(2)%length_x": 2000,  # dlengx,#dlengx/2.+2,   #
             "patch_icpp(2)%length_y": dlengy,
             "patch_icpp(2)%length_z": dlengz,
-            "patch_icpp(2)%a2": interface_amp,
+            "patch_icpp(2)%a(2)": interface_amp,
             "patch_icpp(2)%vel(1)": 0.0e00,
             "patch_icpp(2)%vel(2)": 0.0,
             "patch_icpp(2)%vel(3)": 0.0,