What type of flow pattern would be associated with a forced-convection finned-coil heat exchanger such as an air-cooled hydraulic oil cooler?

Correct Answer: Option D — Cross flow

Cross flow occurs when one fluid flows perpendicular to the other. In a finned-coil heat exchanger, the hydraulic oil flows through the tubes while the cooling air is forced across the exterior fins at a 90-degree angle, maximizing heat transfer efficiency through increased surface area and turbulence.