Numerical investigation of fast precooling of a cylindrical food product based on the hyperbolic heat conduction model

2013 ◽  
Vol 23 (6) ◽  
pp. 960-978 ◽  
Author(s):  
Mohammed Q. Al‐Odat
Keyword(s):  
Heat Conduction ◽  
Heat Generation ◽  
Internal Heat ◽  
Food Product ◽  
Heat Diffusion ◽  
Numerical Code ◽  
Hyperbolic Model ◽  
Hyperbolic Heat Conduction ◽  
Conduction Model ◽  
Content Type

PurposeIn this study, the purpose was to introduce two‐dimensional hyperbolic heat conduction equations in order to simulate the fast precooling process of a cylindrically shaped food product with internal heat generation. A modified model for internal heat generation due to respiration in the food product was proposed to take the effect of relaxation time into account. The obtained governing equations were solved numerically using an efficient finite difference technique. The influence of Biot number and heat generation parameters on thermal characteristics was examined and discussed. The results based on hyperbolic model were compared with the classical parabolic heat diffusion model. The present numerical code was validated via comparison with analytical solution and a good agreement was found.Design/methodology/approachThe obtained governing equations were solved numerically using an efficient finite difference technique.FindingsThe influence of Biot number and heat generation parameters on thermal characteristics was examined and discussed. The results based on hyperbolic model were compared with the classical parabolic heat diffusion model. The present numerical code was validated via comparison with analytical solution and a good agreement was found.Originality/valueTwo‐dimensional analysis of fast precooling of cylindrical food product based on hyperbolic heat conduction model has not been investigated yet.

Transient Heat Transfer in Microscale Porous Materials Heated by Microsecond Laser Pulse of High Power Density

2002 ◽  
Author(s):  
Fangming Jiang ◽  
Dengying Liu ◽  
Jim S.-J. Chen ◽  
Richard S. Cohen
Keyword(s):  
Heat Transfer ◽  
Heat Conduction ◽  
Laser Pulse ◽  
Power Density ◽  
High Power ◽  
Hyperbolic Model ◽  
Transient Temperature ◽  
Hyperbolic Heat Conduction ◽  
High Power Density ◽  
High Heat Transfer

A novel experimental method was developed to measure the rapid transient temperature variations (heating rate > 107 K/s) of porous samples heated by high surface heat fluxes. With a thin film (0.1 μm thick) resistance thermometer of platinum as the temperature sensor and a super-high speed digital oscilloscope (up to 100 MHz) as the data recorder, rapid transient temperature variation in a porous material heated by a microsecond laser pulse of high power density is measured. Experimental results indicate that for high heat transfer cases (q′ > 109 W/m2) with short durations (5 – 20 μs) of heating, non-Fourier heat conduction behaviors appear. The non-Fourier hyperbolic heat conduction model and the traditional Fourier parabolic model are employed to simulate this thermal case respectively and the FDM is used to perform the numerical analysis. The hyperbolic model predicts thermal wave behavior in qualitative agreement with the experimental data.

Overshooting Phenomenon in the Hyperbolic Heat Conduction Model

2003 ◽  
Vol 42 (Part 1, No. 8) ◽  
pp. 5383-5386 ◽  
Author(s):  
Mohammad Al-Nimr ◽  
Malak Naji ◽  
Salem Al-Wardat
Keyword(s):  
Heat Conduction ◽  
Hyperbolic Heat Conduction ◽  
Conduction Model ◽  
Heat Conduction Model

Double-diffusive natural convection in an inclined enclosure with heat generation and Soret effect

2018 ◽  
Vol 35 (8) ◽  
pp. 2753-2774 ◽  
Author(s):  
Safae Hasnaoui ◽  
Abdelkhalek Amahmid ◽  
Abdelghani Raji ◽  
Hassen Beji ◽  
Mohammed Hasnaoui ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Fluid Flow ◽  
Natural Convection ◽  
Finite Difference ◽  
Heat Generation ◽  
Soret Effect ◽  
Internal Heat ◽  
Vertical Position ◽  
Fluid Temperature ◽  
Content Type

PurposeThe purpose of this paper is to study numerically thermosolutal natural convection within an inclined rectangular cavity in the presence of Soret effect and heat generation. The enclosure is heated and salted from its long sides with constant but different temperatures and concentrations. The study focuses on the effects of three main parameters which are, the Soret parameter (Sr = 0 and –0.5), the internal to external Rayleigh numbers ratio 0 ≤ R ≤ 80 and the cavity inclination γ, varied from 0° (vertical position) to 60°. The combined effects of these parameters on fluid flow and heat and mass transfer characteristics are examined for the external Rayleigh numberRaE = 105, the Prandtl numberPr = 0.71, the buoyancy ratioN = 1, the Lewis numberLe = 2 and the aspect ratio of the cavityA = 2.Design/methodology/approachA hybrid lattice Boltzmann-finite difference method (LBM-FD) was used to tackle the problem under consideration. The LBM with the simple relaxation time was used for the fluid flow in the presence of the gravity force, while the temperature and concentration equations were solved separately using an explicit finite-difference technique at the Boltzmann scale.FindingsThe monocellular nature of the flow, obtained forR = 0 is not destroyed by varying the cavity inclination and the Soret parameter but rather by the increase of the parameter R. The Soret parameter and the cavity inclination become perceptible at high values ofR. The inclinationγ = 60° leads to high mean temperatures compared to the other inclinations. The effect ofRon mean concentration is amplified in the presence of Soret effect but limited in the absence of the latter. The negative Soret parameter combined with high internal heat generation and a relatively high inclination is important when the objective is to maintain the fluid at a high concentration of species. The presence of bicellular flow combined with the important elevation undergone by the fluid temperature, makes both the cold and hot walls playing a cooling role with the most important exchanges taking place at the upper part of these walls. The analysis of the mean mass transfer shows that the increase of the inclination may lead to an increase or a decrease of the mass transfer depending on the range ofR, in the case of Sr = 0. However, for Sr = −0.5, it is observed that the increase ofγis generally accompanied by a reduction of the mass transfer.Originality/valueTo the best of the authors’ knowledge, the hybrid LBM-FD was not used before to study such a problem. Combined effect ofRand inclination may be useful in charging the fluid with species when the objective is to maintain high concentrations in the medium.

Refined bond-based peridynamics for thermal diffusion

2019 ◽  
Vol 36 (8) ◽  
pp. 2557-2587 ◽  
Author(s):  
Xin Gu ◽  
Qing Zhang ◽  
Erdogan Madenci
Keyword(s):  
Heat Conduction ◽  
Differential Operator ◽  
Thermal Conduction ◽  
Calibration Procedure ◽  
Classical Solutions ◽  
Refined Model ◽  
Conduction Model ◽  
Content Type ◽  
Integral Forms ◽  
Cracked Structures

Purpose This paper aims to review the existing bond-based peridynamic (PD) and state-based PD heat conduction models, and further propose a refined bond-based PD thermal conduction model by using the PD differential operator. Design/methodology/approach The general refined bond-based PD is established by replacing the local spatial derivatives in the classical heat conduction equations with their corresponding nonlocal integral forms obtained by the PD differential operator. This modeling approach is representative of the state-based PD models, whereas the resulting governing equations appear as the bond-based PD models. Findings The refined model can be reduced to the existing bond-based PD heat conduction models by specifying particular influence functions. Also, the refined model does not require any calibration procedure unlike the bond-based PD. A systematic explicit dynamic solver is introduced to validate 1 D, 2 D and 3 D heat conduction in domains with and without a crack subjected to a combination of Dirichlet, Neumann and convection boundary conditions. All of the PD predictions are in excellent agreement with the classical solutions and demonstrate the nonlocal feature and advantage of PD in dealing with heat conduction in discontinuous domains. Originality/value The existing PD heat conduction models are reviewed. A refined bond-based PD thermal conduction model by using PD differential operator is proposed and 3 D thermal conduction in intact or cracked structures is simulated.

Sign in / Sign up

Export Citation Format

Share Document