One of the ways to reduce energy consumption on the air plane and the other bluff bodies are by decreasing the drag. Dragis closely related to the flow separation. The earlier separation. then the drag will increase more. https://www.roneverhart.com/Western-Digital-Ultrastar-DC-HC570-WUH722222ALE6L4-0F48155-22TB-7-2K-RPM-SATA-6Gb-s-512e-SE-3-5in-Refurbished-HDD/