fix arcs: z coordinate

openfoam/run/flowAroundCylinder/system/blockMeshDict

@@ -71,7 +71,7 @@ vertices
     name Fns (20 0 0)
     name Bns (20 0 $thickness)
     name Fnm (0 0 0)
-    name Bnm (0 0 1)
+    name Bnm (0 0 $thickness)
 );
 
 blocks
@@ -89,10 +89,10 @@ edges
     arc Fctl Fctr (0 5 0)    // = Fct
     arc Fctr Fcbr (5 0 0)    // = Fcr
     arc Fcbr Fcbl (0 -5 0)   // = Fcb
-    arc Bcbl Bctl (-5 0 0)   // = Bcl
-    arc Bctl Bctr (0 5 0)    // = Bct
-    arc Bctr Bcbr (5 0 0)    // = Bcr
-    arc Bcbr Bcbl (0 -5 0)   // = Bcb
+    arc Bcbl Bctl (-5 0 $thickness)   // = Bcl
+    arc Bctl Bctr (0 5 $thickness)    // = Bct
+    arc Bctr Bcbr (5 0 $thickness)    // = Bcr
+    arc Bcbr Bcbl (0 -5 $thickness)   // = Bcb
 );
 
 boundary