Coefficients for reflect condition in DPM model for water droplets
 

I am running case with airflow at temperatures of about 500 K with DPM (water droplets). Can anyone guide me on what values of coefficients should I specify in 'reflect' Boundary condition for walls relevant to my case?
Will water droplets just come to rest (coefficient = 0) on striking the surface or have some small values of coefficients? If so what values are typically used for cases similar to mine?