Analysis of a double pipe heat exchanger performance by use of porous baffles and pulsating flow

• A double pipe heat exchanger performance is numerically studied.
• Use of porous baffles and pulsating flow to enhance heat exchanger efficiency.
• The governing equations are solved by the control volume method.
• The efficiency increases with the amplitude and frequency of pulsation.
• The highest values of 〈E〉 are obtained when only hot fluid is pulsating (Case3).

A numerical investigation is carried out to analyze the effect of porous baffles and flow pulsation on a double pipe heat exchanger performance. The hot fluid flows in the inner cylinder, whereas the cold fluid circulates in the annular gap. The Darcy–Brinkman–Forchheimer model is adopted to describe the flow in the porous regions and the finite volume method is used to solve the governing equations with the appropriate boundary conditions. The effects of the amplitude and frequency of pulsation, as well as the porous baffles permeability on the flow structure and the heat exchanger efficiency are analyzed. The results reveal that the addition of an oscillating component to the mean flow affects the flow structure, and enhances the heat transfer in comparison to the steady non pulsating flow. The highest heat exchanger performance is obtained when only the flow of the hot fluid is pulsating.