Three-dimensional linear stability of natural convection in horizontal concentric annuli

Determining the critical condition for turbulent transition in a full-developed annulus flow

“…It is found from Eq. (17) that there is a maximum or minimum of K for given 1 Re , which corresponds to those of f , respectively. Since we concern the magnitude of the minimum or maximum of the function f, no matter how the sign of the minimum or maximum of the function of f for consideration of the flow instability, we take the…”

“…Therefore, this result confirms that the criterion proposed for annulus flow in this study is correct. This confirming route is summarized as follow:(1) obtain the value of Kc from experimental data of pipe flow, say Kc=385; (2) derive the formulation of Re for annulus flow; (3) put this value of Kc into the equation of annulus flow as a criterion; (4) calculate the critical Re for annulus flow and plot it in the figure; (5) obtain the critical Re of plane Poiseuille flow by extrapolating the data of annulus flow to k=1. As we have seen, the predicted critical Re for plane Poiseuille flow is in perfectly consistent with the experimental data.…”

“…The full developed turbulence flow was simulated using LES (large eddy simulation) method (Lee et al, 2004;Padilla and Silveira-Neto, 2008). Linear stability analysis has been used to study the instability and transition under the convective heat transfer (Dyko et al, 1999; Labonia ang Guj, 1998; Petrone et al, 2006;Adachi and Imai, 2007). The friction factor in the annulus under natural convective flow has been measured in (Lu and Wang, 2008).…”

Analysis of conduction – natural convection conjugate heat transfer in the gap between concentric cylinders under solar irradiation

“…J.C. Leong et al [23] studied the natural convection in a concentric annulus with a porous sleeve. Takahiro Adachi et al [24] studied the three-dimensional linear stability natural convection in horizontal concentric annuli. Khalil Khanafer et al [25] studied the Numerical analysis of natural convection heat transfer in a horizontal annulus partially filled with a fluidsaturated porous substrate.…”

Transient Natural Convection in an Annulus with Thermal Radiation

“…Also [6] discussed the existence of dual solution and role of Prandtl number on bifurcation. [7] performed three-dimensional linear stability analysis of air in horizontal concentric annuli between concentric cylinders by using a spectral method. In [8], finite difference method in conjunction with least-squares scheme and experimental temperature data is used to predict the average heat transfer coefficient and fin efficiency on the fin of annular-fined tube.…”