Numerical simulation of a solar collector equipped with a twisted tape and containing a hybrid nanofluid

Abstract

Increasing demand for energy in the world has made renewable energies so crucial. Solar energy, as the widest and accessible type of renewable energy, is now developed consistently. Solar energy is received and concentrated by equipment made of surficial mirrors. Complete transferring of solar heat flux to the working fluid is a challenge and there have been performed some efforts to enhance the performance of solar heat transfer. Following this goal, the current work numerically investigates heat transfer enhancement in a solar collector exposed to a non-uniform thermal flux. This is fulfilled by considering a hybrid nanofluid in the turbulent collector flow that contains a twisted tape. The effects of Reynold number, the volume fraction of nanoparticles, and wall roughness are detected. It is shown that can be increased up to 23 and 90 percent by rising the volume friction of the hybrid nanofluid and wall roughness of the collector tube, respectively. The pressure distribution in the collector shows a completely different pattern in the part where the wall is heated and the other adiabatic part. This can address an extra force, applying on the twisted tape, which requires consideration.