They use a wall with a no-slip boundary having complete wetting (contact angle = 0°) and a constant wall temperature to compare with the Nusselt film theory. I have set the exact same conditions shown here:

By the way, the contact angle set here is 180° as I've set the condensate as the primary phase and the vapour as the secondary phase. And sorry b) is pressure-outlet with a backflow temperature equal to the saturation temperature. I'm not using outflow anymore.