Altered or uninterrupted forward flow found at bifurcations and mild obstructions is best described as which flow type?

• A. Disturbed flow
• B. Laminar flow
• C. Turbulent flow
• D. Plug flow

Answer: (A)

Disturbed flow is the flow pattern you see when the vessel geometry disrupts smooth, parallel layers without flipping the direction of travel. At bifurcations or near mild obstructions, the streamlines become irregular and the velocity profile loses its perfectly smooth shape, yet the overall flow remains forward. This sits between laminar and turbulent flow: not entirely smooth, but not chaotic enough to reverse or swirl extensively. Laminar flow would be a neat, layered flow with a smooth velocity profile; turbulent flow would show chaotic eddies and wide fluctuations in direction and speed; plug flow implies a flat velocity profile across the cross-section, which isn’t what occurs at these geometrical features. Therefore, the described situation best fits disturbed flow.