r. hekmatkhah

The analysis of heat transfer in the channel in many types of heat exchangers, such as electric cooling equipment, solar collectors, heat exchanger systems, high-performance boilers, gas turbine blade coolers, etc., is the basis of the design, construction, and optimization. Controlling heat transfer to increase the rate of heat transfer in such systems by improving the cooling method is an effective energy engineering from the point of saving energy. Increasing the heat transfer performance in the scales of macro and microchannels is crucial. The use of expanded surfaces in the channel is a practical method to increase the heat transfer coefficient. In the upcoming article, the smart design of a two-dimensional nanofluid heat exchanger has been studied numerically in order to achieve optimal performance conditions in terms of heat transfer rate, the amount of deposition of nanoparticles in the structure of the exchanger, as well as the fluid pressure drop while passing through it. It can be seen that the geometric structure optimized by the combination of genetic algorithm and computational fluid dynamics of this channel causes an increase of 1.14% in the enthalpy of the passing nanofluid, a decrease of 11.21% in the pressure drop of the passing nanofluid, and a reduction of 8.44% percentage in the deposition of nanoparticles inside the channel and a total increase of 24.82% in the fitting function defined in terms of these three variables, compared to the channel designed in previous studies. Therefore, this optimal channel has a higher heat transfer rate with a pressure drop and a lower amount of nanoparticle deposition compared to the previous channel, which proves the ability of the genetic algorithm with computational fluid dynamics in the optimal design of all types of heat exchangers.

The vapour absorption into the liquid falling film has occurred in various natural phenomena and its application has spread in various industries, such as the dehumidification and desalination industry. The complexity of flow dynamics, mass transfer, heat, and small dimensions of a liquid film has made its modeling and numerical simulation a key role in the investigation and studying of the effectiveness and improvement of the absorption process in a liquid film absorbent. In the present work, the effects of Reynolds number, wall temperature, and wall shape on the interfacial heat and mass transfer have been investigated. Numerical modeling has been performed using an unsteady Arbitrary Lagrangian-Eulerian interface tracking method by Fortran. The simulation results show that the deformation of the wall surface and the cooling of the wall temperature has a significant effect on the rate of gas vapor absorption into the laminar liquid film in comparison with the flat wall