| An analytical and experimental study of laminar free convection from bodies of arbitrary convex shape is performed to determine the effect of shape, aspect ratio and orientation of isothermal bodies on the area-averaged Nusselt number over a wide range of Rayleigh and Prandtl numbers. Also, a simple procedure is provided for predicting laminar free convection heat transfer from bodies of arbitrary convex shape, based upon a characteristic length using the square root of the total body surface area, ;By providing different exact and approximate methods, such as the same characteristic lengths and aspect ratios method or the inscribing and circumscribing method (the bounds method), the two asymptotes can be determined for any given shape. This includes body shapes such as the so-called two-dimensional bodies, disks, bodies of small aspect ratios and vertical cylinders of different aspect ratios.;In the experimental program, through a transient cooling process and pressure variation technique, the measurement of heat transfer by free convection from isothermal bodies to air is conducted.;Due to the nature of the experimental technique adopted and the need for the heat capacity, in a separate and single test at pressures below 10;To examine the theoretical basis for the ;The predictions of the present study are compared with the experimental data of the present study and other sources; very good agreement in almost all of the cases is observed.;The simplicity, generality and accuracy used in the analytical models make the proposed method superior for predicting free convection heat transfer from isothermal convex bodies for the laminar range of Ra and all Prandtl numbers. (Abstract shortened by UMI.). |
