Effective thermal conductivity of disperse media at small peclet number

1976 ◽  
Vol 31 (4) ◽  
pp. 1141-1145 ◽  
Author(s):  
Yu. A. Buevich ◽  
Yu. A. Korneev
Keyword(s):  
Thermal Conductivity ◽  
Effective Thermal Conductivity ◽  
Peclet Number ◽  
Péclet Number

Finite element thermal analysis of a moving porous fin with temperature-variant thermal conductivity and internal heat generation

2020 ◽  
Vol 1 (1) ◽  
pp. 110
Author(s):  
Gbeminiyi Sobamowo ◽  
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Finite Element ◽  
Heat Generation ◽  
Peclet Number ◽  
Numerical Solutions ◽  
Internal Heat ◽  
Internal Heat Generation ◽  
Péclet Number ◽  
Porous Fin

This paper focuses on finite element analysis of the thermal behaviour of a moving porous fin with temperature-variant thermal conductivity and internal heat generation. The numerical solutions are used to investigate the effects of Peclet number, Hartmann number, porous and convective parameters on the temperature distribution, heat transfer and efficiency of the moving fin. The results show that when the convective and porous parameters increase, the adimensional fin temperature decreases. However, the value of the fin temperature is amplified as the value Peclet number is enlarged. Also, an increase in the thermal conductivity and the internal heat generation cause the fin temperature to fall and the rate of heat transfer from the fin to decrease. Therefore, the operational parameters of the fin must be carefully selected to avoid thermal instability in the fin.

scholarly journals Magneto-Burgers Nanofluid Stratified Flow with Swimming Motile Microorganisms and Dual Variables Conductivity Configured by a Stretching Cylinder/Plate

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Hassan Waqas ◽  
Umair Manzoor ◽  
Zahir Shah ◽  
Muhammad Arif ◽  
Meshal Shutaywi
Keyword(s):  
Thermal Conductivity ◽  
Activation Energy ◽  
Brownian Motion ◽  
Peclet Number ◽  
Current Model ◽  
Lewis Number ◽  
Motion Parameter ◽  
Stretching Cylinder ◽  
Péclet Number ◽  
Brownian Motion Parameter

Background. The study of nanofluid gains interest of researchers because of its uses in treatment of cancer, wound treatment, fuel reserves, and elevating the particles in the bloodstream to a tumour. This artefact investigates the magnetohydrodynamic flow of Burgers nanofluid with the interaction of nonlinear thermal radiation, activation energy, and motile microorganisms across a stretching cylinder. Method. The developed partial differential equations (PDEs) are transformed into a structure of ODEs with the help of similarity transformation. The extracted problem is rectified numerically by using the bvp4c program in computational software MATLAB. The novelty of analysis lies in the fact that the impacts of bioconvection with magnetic effects on Burgers nanofluid are taken into account. Moreover, the behaviours of thermal conductivity and diffusivity are discussed in detail. The impacts of activation energy and motile microorganism are also explored. No work has been published yet in the literature survey according to the authors’ knowledge. The current observation is the extension of Khan et al.’s work [51]. Results. The consequences of the relevant parameters, namely, thermophoresis parameter, Brownian motion parameter, the reaction parameter, temperature difference parameter, activation energy, bioconvection Lewis number and Peclet number against the velocity of Burgers nanofluid, temperature profile for nanoliquid, the concentration of nanoparticles, and microorganisms field, have been explored in depth. The reports had major impacts in the development of medications for the treatment of arterial diseases including atherosclerosis without any need for surgery, which may reduce spending on cardiovascular and postsurgical problems in patients. Conclusions. The current investigation depicts that fluid velocity increases for uplifting values of mixed convection parameter. Furthermore, it is analyzed that flow of fluid is risen by varying the amount of Burgers fluid parameter. The temperature distribution is escalated by escalating the values of temperature ratio parameter and thermal conductivity parameter. The concentration field turns down for elevated values of Lewis number and Brownian motion parameter, while conflicting circumstances are observed for the thermophoresis parameter and solutal Biot number. Larger values of Peclet number reduce the microorganism’s field. Physically the current model is more significant in the field of applied mathematics. Furthermore, the current model is more helpful to improve the thermal conductivity of base fluids and heat transfer rate.

The Effects of Forced Convection on the Power Dissipation of Constant-Temperature Thermal Conductivity Sensors

1997 ◽  
Vol 119 (1) ◽  
pp. 30-37 ◽  
Author(s):  
Y. Huang ◽  
H. H. Bau
Keyword(s):  
Thermal Conductivity ◽  
Forced Convection ◽  
Constant Temperature ◽  
Power Dissipation ◽  
Peclet Number ◽  
Asymptotic Theory ◽  
Time Dependent ◽  
Péclet Number ◽  
Theoretical Predictions ◽  
On Line

The effect of forced convection on the power dissipation of cylindrical and planar, constant temperature, thermal conductivity detectors (TCDs) is investigated theoretically. Such detectors can be used either for on-line continuous sensing of fluid thermal conductivity or for determining the sample concentrations in gas chromatography. A low Peclet number, asymptotic theory is constructed to correlate the TCD’s power dissipation with the Peclet number and to explain experimental observations. Subsequently, the effect of convection on the TCD’s power dissipation is calculated numerically for both time-independent and time-dependent flows. The theoretical predictions are compared with experimental observations.

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