Heat transfer and fluid flow analysis of solar air heater: A review of CFD approach

The objective of this article is to present a detailed review of the literature that deals with the application of CFD in the design of solar air heater. Solar air heater is one of the basic equipment through which solar energy is converted into thermal energy. CFD is a simulation tool which uses powerful computer and applied mathematics, to model fluid flow situations for the prediction of heat, mass and momentum transfer and optimal design in various heat transfer and fluid flow processes. The quality of the solutions obtained from CFD simulations are largely within the acceptable range proving that CFD is an effective tool for predicting the behavior and performance of a solar air heater. One of the great challenges in the design of a solar air heater using CFD approach is the selection of appropriate turbulence model. The decision about a suitable turbulence model chosen in a CFD computation is not easy. In this article a CFD investigation is also carried out to select best turbulence model for the design of a solar air heater. A modern CFD code ANSYS FLUENT v12.1 is used to simulate fluid flow through a conventional solar air heater. A two-dimensional flow is assumed. The influences of the five different turbulence models on the quality of the obtained results are tested. It appears from the performed calculations that the Renormalization-group k–ε model yields the best results for two-dimensional flow through conventional solar air heaters.