A quick post, for my reference

You have a physical server with a HBA & LUNs presented from a SAN. What's the WWN of a specific LUN?

PS> (Get-WMIObject -Namespace root\wmi -Class mpio_disk_info).DriveInfo | Select-Object Name, SerialNumber

Capture-1-
The "SerialNumber" is the WWN. Happy days :)