A scavenge tube for conveying oil within an engine. The scavenge tube includes an outer tube and an inner tube. The outer tube defines a first surface and the inner tube defines a second surface. The inner tube is configured to be fluidly connected to a source for oil. A space that is defined between the outer tube and the inner tube such that the first surface opposes the second surface. A plurality of bumps is positioned within the space such that each bump extends from one of the first surface and the second surface and extends toward the opposing surface.