On the optimal heat source location of partially heated energy storage process using the newly developed simplified enthalpy based lattice Boltzmann method

Thermal energy storage (TES) systems are much preferred in many engineering applications, which have the ability to overcome the mismatch between energy supply and energy demand. TES can be used to store thermo-chemical, sensible, or latent heat or a combination of these. Among the three forms, latent heat thermal energy storage (LHTES) has grown considerably in importance over recent years as a promising alternative to traditional systems. These systems use phase change materials (PCM), in simple or cascade configuration, and store the latent heat of melting (charging process) and release it during solidification (discharging process). Among different configurations of LHTES systems, tube and shell heat exchangers represent a promising and simple design in high temperature PCM. In this paper, we present a new numerical study involving a tube and shell heat exchanger to evaluate the heat storage phenomena. A case study and numerical results are provided using the Lattice Boltzmann Method.

Download Full-text

Effects of cavity and heat source aspect ratios on natural convection of a nanofluid in a C-shaped cavity using Lattice Boltzmann method

International Journal of Numerical Methods for Heat &amp Fluid Flow ◽

10.1108/hff-03-2018-0110 ◽

2018 ◽

Vol 28 (8) ◽

pp. 1930-1955 ◽

Cited By ~ 33

Author(s):

Mohsen Izadi ◽

Rasul Mohebbi ◽

A. Chamkha ◽

Ioan Pop

Keyword(s):

Nusselt Number ◽

Natural Convection ◽

Rayleigh Number ◽

Aspect Ratio ◽

Heat Source ◽

Lattice Boltzmann Method ◽

Lattice Boltzmann ◽

Average Nusselt Number ◽

Content Type ◽

Boltzmann Method

PurposeThe purpose of this paper is to consider natural convection of a nanofluid inside of a C-shaped cavity using Lattice Boltzmann method (LBM).Design/methodology/approachEffects of some geometry and flow parameters consisting of the aspect ratio of the cavity, aspect ratio of the heat source; Rayleigh number (Ra = 103− 106) have been investigated. The validity of the method is checked by comparing the present results with ones from the previously published work.FindingsThe results demonstrate that for Ra = 103, the aspect ratio of the heat source has more influence on the average Nusselt number in contrast to the case of Ra = 106. Contrary to the fact that the average Nusselt number increases non-linearly more than twice because of the increase of the aspect ratio of the enclosure at Ra = 103, the average Nusselt number has a linear relation with the aspect ratio for of Ra = 106. Therefore, upon increasing the Rayleigh number, the efficiency of the aspect ratio of the cavity on the thermal convection, gradually diminishes.Originality/valueThe authors believe that all the results, both numerical and asymptotic, are original and have not been published elsewhere.

Download Full-text

Simulation of Thermal Flow Problems via a Hybrid Immersed Boundary-Lattice Boltzmann Method

Journal of Applied Mathematics ◽

10.1155/2012/161484 ◽

2012 ◽

Vol 2012 ◽

pp. 1-11 ◽

Cited By ~ 2

Author(s):

J. Wu ◽

C. Shu ◽

N. Zhao

Keyword(s):

Boundary Condition ◽

Temperature Field ◽

Heat Source ◽

Lattice Boltzmann Method ◽

Lattice Boltzmann ◽

Source Term ◽

Immersed Boundary ◽

Thermal Flow ◽

Flow Problems ◽

Boltzmann Method

A hybrid immersed boundary-lattice Boltzmann method (IB-LBM) is presented in this work to simulate the thermal flow problems. In current approach, the flow field is resolved by using our recently developed boundary condition-enforced IB-LBM (Wu and Shu, (2009)). The nonslip boundary condition on the solid boundary is enforced in simulation. At the same time, to capture the temperature development, the conventional energy equation is resolved. To model the effect of immersed boundary on temperature field, the heat source term is introduced. Different from previous studies, the heat source term is set as unknown rather than predetermined. Inspired by the idea in (Wu and Shu, (2009)), the unknown is calculated in such a way that the temperature at the boundary interpolated from the corrected temperature field accurately satisfies the thermal boundary condition. In addition, based on the resolved temperature correction, an efficient way to compute the local and average Nusselt numbers is also proposed in this work. As compared with traditional implementation, no approximation for temperature gradients is required. To validate the present method, the numerical simulations of forced convection are carried out. The obtained results show good agreement with data in the literature.

Download Full-text