In a heat exchanger, what is the function of baffles?

In a heat exchanger, the function of baffles is to increase the flow path and turbulence for better heat transfer. Baffles are strategically placed within the heat exchanger to direct the flow of the fluids. By doing this, they spell out a longer and more complicated pathway for the fluids, which ensures that the fluids have a greater surface area contact with the heat transferring surfaces.

Increased turbulence promotes mixing and enhances the heat transfer coefficient, as turbulent flow reduces the thermal boundary layer thickness on the heat transfer surfaces. The combination of these effects significantly improves the overall heat exchange efficiency. The design of baffles helps in maintaining optimal flow patterns that are necessary for effective temperature transfer between the two fluids within the heat exchanger.

While the other options suggest related concepts—like fluid velocity and flow direction—none of them encapsulate the primary purpose of baffles as effectively as the chosen answer does.