SPH modeling of natural convection in horizontal annuli

Natural convection in horizontal annuli is widely used in engineering applications. This paper numerically investigates natural convection in horizontal annuli using smoothed particle hydrodynamics (SPH). Experimental and numerical findings of concentric and eccentric horizontal annuli from the literature were used to validate the SPH method. Different cases were studied by changing two dimensionless parameters, namely, the radius ratio and Rayleigh number. Three convection states were identified from numerical simulations with different radius ratios and Rayleigh numbers, namely, no plume, one plume and two plumes. The numerical results indicated that the plume is generated when the Rayleigh number is in the order of 10⁴ or larger and that a high radius ratio limits the development of the plume and the strength of natural convection was reduced. The direction and number of the plumes fluctuated as the inner cylinder travels in different directions and the eccentricity changes. [Figure not available: see fulltext.]