correct readme

11145_pebble_yuhsiang_E3p5M/README.md

@@ -19,7 +19,7 @@ Please note that the improvement has not finished.
   - Fix some bugs as well  
 
 - Geometry and BC:
-  - Sphere distribution: flat-free
+  - Sphere distribution: free-free
   - Sphere radius = 1.0 (Wall)
   - Cylinder radius = 40.672 (SYM), (convert SYM to Wall in usr file)
   - Zbot of the cylinder =  14.655 (Outflow)