Computer-aided 3D simulation and visualization are important industrial art extensively used in many applications, including automotive, shipbuilding, and aerospace industries, industrial and architectural design, prosthetics, and many more. The HCI Lab at UCF takes advantages of its powerful computer systems and facilities and also experienced members in this area to do graphical postprocessing of the designed or simulated projects. This project shows the flow streamlines of a shell and tube heat exchanger (HEX). The hot water enters into the shell side of the HEX and after exchanging heat with the cold flow in the tubes and getting cold, exits on the other side. Colorful vectors show the path of the flow and magnitude of the velocity.