LAUSR

In this study, laminar unsteady two-dimensional incompressible nanofluid flow is numerically investigated over a heated circular cylinder under angular oscillations about its own axis. Governing equations include Navier–Stokes, and energy equations have been solved numerically using finite volume method. Simulations were carried out in $$100 \le Re \le 200$$ 100 ≤ R e ≤ 200 , $$0.5 \le F \le 2$$ 0.5 ≤ F ≤ 2 and $$\varTheta_{\text{A}} = {\raise0.7ex\hbox{$\pi $} \!\mathord{\left/ {\vphantom {\pi 4}}\right.\kern-0pt} \!\lower0.7ex\hbox{$4$}} , {\raise0.7ex\hbox{$\pi $} \!\mathord{\left/ {\vphantom {\pi 2}}\right.\kern-0pt} \!\lower0.7ex\hbox{$2$}}$$ Θ A = π / 4 , π / 2 . Also CuO–water nanofluid was utilized in various volume fractions of $$0 \le \varphi \le 3\%$$ 0 ≤ φ ≤ 3 % range. Thermophysical properties of nanofluid were assumed to be temperature dependent. Lock-on phenomenon has been detected and its effects on the fluid flow, and heat transfer characteristics have been illustrated. The effects of solid particles volume fraction and oscillation parameters on the vortex shedding, mean velocity contours, mean drag and lift coefficients, temperature field, heat transfer coefficient and power spectral density diagrams have been investigated in detail. Obtained results indicate that utilization of nanofluids is more preferable, since oscillating the cylinder leads to dissipation in engineering equipments which would deduce the efficiency compared to using nanofluids.