Numerical evaluation of heat transfer in corrugated heat exchangers

In this study, we carried out several simulations by investigating numerically an important geometrical factor in the corrugated tubes, very known in heat exchangers technology and applied in solar and desalination plants, specifically we focused our interest on the influence of the pitch length parameter over the heat transfer in these tubes using CFD (ANSYS/FLOTRAN). The used duct is a cylindrical pipe and the hecklers are spherical cavities. The 2d axisymmetric model is used and the model k-epsilon turbulence is adopted. The working fluid is water, and the usual boundary conditions such as outlet pressure and wall temperature are fixed. Based on the numerical results obtained in this study, it is found that for small pitches, the grooves produce more turbulence but away from the walls, unlike the case of large pitch. Besides, the variation of the heat transfer efficiency according to the pitch length for various velocities is presented and analyzed. It is revealed that the positive effect of the pitch is not always found.