Positioning Effect on Free Convection with an Elliptical Plate Placed in a Circular Enclosure

In this analysis we have examined the process of the steady state laminar natural convection around heated elliptical plate with Rayleigh number 10^6 positioned inside a circular enclosure. The purpose of the numerical analysis is to analyze the behavior of isotherms, streamlines and heat transfer rate in enclosure plate system due to the variation in the position of elliptical plate (r/D =0.00, 0.05, and 0.2) and aspect ratio, where the given diameter of the enclosure is D and r is the distance between the centre of elliptical plate and centre of circle. Elliptical plate is inclined at different angles and results are summed up in relative manner. There are two cases, in first case aspect ratio a/D and b/D is varied and D is kept constant, whereas in second case aspect ratio a/D and b/D is kept constant and D is varied. Temperature difference between the enclosure and the inner body (i.e., temperature of inner body is kept high as compared to the enclosure) is maintained. Two dimensional study is followed by considering air as a fluid in enclosure. The effects of the Heat Transfer and Flow of Fluid are analyzed by the streamlines and isotherms plotted for the body placed inside enclosure. Value of local Nusselt number (Nu) is also plotted along the wall of elliptical plate and along the surface of the circular enclosure. For every aspect ratio isotherms and streamlines had been plotted. This work has been validated with various other numerical studies and was in good conciliation.

Direct Numerical Simulation of Laminar Natural Convection in a Square Cavity at Different Inclination Angle

The effect of angle of rotation on laminar natural convection inside the square cavity have been observed in this research. It was assumed that left and right walls heated isothermally, whereas other two walls act as adiabatic. This problem was solved by assuming 2-D and by Direct Numerical Simulation (DNS) method using ANSYS Fluent 16.0. A series of DNS simulation were carried out for different inclination angle (𝜃 = 0°~90°) of the cavity at Ra = 103 & 104. It was observed that at average Nusselt number increase up to some value of angle of inclination after that it decrease though this variation is not significant.