Hello James Cho
There is currently no option to specify wall roughness in Discovery Live.
What pressure drop value are you getting in Discovery Live and CFX? Did you run the model with highest fidelity in Discovery Live? How much graphics card memory do you have? Can you share the Discovery Live project file with all the BCs defined? Please note that results of Discovery Live are not intended to be compared with other solver results for accuracy, but to explore rapid design changes and understand the trends of results.