Investigation of a temperature-sensitive ferrofluid to predict heat transfer and irreversibilities in LS-3 solar collector under line dipole magnetic field and a rotary twisted tape

This article numerically studies the performance of the LS-3 parabolic trough collector. The parabolic trough solar system is equipped with an innovative rotary twisted tape. The absorber tube and twisted tape have the same length. Moreover, line dipole magnetic field is applied to improve the performance of solar collector. In addition, the characteristics of the irreversibilities are investigated. Commercial temperature-sensitive ferrofluid is selected for working fluid, and the nanoparticles along with the base fluid assumed to be uniform. The effect of rotational speed, twisted ratio, and line dipole magnetic field are compared with plain tube. The heat flux profile on absorber tube is ascertained by the Monte Carlo Ray Tracing method. Curve fitting method is used to obtain the mathematical function of the heat flux profile. To solve the equations including continuity, momentum, energy, and SST κ − ω model, the finite volume procedure is selected. The more convective heat transfer coefficient occurs by dipole magnetic field, the maximum enhancement reaches over 97% at B = 100 G. In addition, the twisted tape can increase heat transfer by 305% at twisted ratio = 2.5 and rotational speed = 200 rpm. Furthermore, if the twisted tape has rotational speed, the thermal entropy generation decreases.