Add comments for hydrodynamic coefficients

Author: stevenjgibbons

setrun.py

@@ -16,8 +16,8 @@
 gamma_r = 100.0        # Reference strain rate
 c_mass = 0.1          # Added Mass
 hydrodrag = True      # Use hydrodrag force?
-cF_hyd = 0.01
-cP_hyd = 1.0
+cF_hyd = 0.01         # Hydrodynamic friction coefficient
+cP_hyd = 1.0          # Hydrodynamic pressure coefficient
 remolding = True     # remolding? if not, only tauy_i is used
 tauy_i =   12000.0   # initial yield strength (Pa)
 tauy_r =   3000.0    # residual yield strength (Pa)