Effect of angle of incidence on mixed convective wake dynamics and heat transfer past a square cylinder in cross flow at Re = 100

Abstract

In this paper, a numerical investigation is performed to study the mixed convective flow and heat transfer characteristics past a square cylinder in cross flow at incidence. Utilizing air (Pr=0.71) as an operating fluid, computations are carried out at a representative Reynolds number (Re) of 100. Angles of incidences are varied as, 0°⩽α⩽45°. Effect of superimposed positive and negative cross-flow buoyancy is brought about by varying the Richardson number (Ri) in the range −1.0⩽Ri⩽1.0. The detail features of flow topology and heat transport are analyzed critically for different angles of incidences. The thermo fluidic forces acting on the cylinder during mixed convection are captured in terms of the drag (CD), lift (CL), and moment (CM) coefficients. The results show that the lateral width of the cylinder wake reduces with increasing α and the isotherms spread out far wide. In the range 0°<α<45°, CD reduces with increasing Ri. The functional dependence of CM with Ri reveals a linear relationship. Thermal boundary layer thickness reduces with increasing angle of incidences. The global rate of heat transfer from the cylinder increases with increasing α.