Heat-conduction error of temperature sensors in a fluid flow with nonuniform and unsteady temperature distribution

2013 ◽  
Vol 84 (4) ◽  
pp. 044902 ◽  
Author(s):  
Soe Minn Khine ◽  
Tomoya Houra ◽  
Masato Tagawa
Keyword(s):  
Fluid Flow ◽  
Heat Conduction ◽  
Temperature Distribution ◽  
Temperature Sensors ◽  
Unsteady Temperature ◽  
Conduction Error

Temperature Distribution and Fluid Flow Modeling of Electron Beam Melting® (EBM)

2012 ◽  
Author(s):  
M. Jamshidinia ◽  
F. Kong ◽  
R. Kovacevic
Keyword(s):  
Electron Beam ◽  
Fluid Flow ◽  
Temperature Distribution ◽  
Molten Pool ◽  
Electron Beam Melting ◽  
Control Volume ◽  
Thermal Analyses ◽  
Scanning Speed ◽  
Flow Modeling ◽  
Fluid Flow Modeling

A three-dimensional (3D) numerical model is developed by using control volume method to analyze the effects of the electron beam scanning speed on the temperature distribution and fluid flow of the liquid phase in the electron beam melting® (EBM) of Ti-6Al-4V powder. The numerical calculations are performed by Fluent codes, in which thermal analyses with and without considering fluid flow in the molten pool are compared. A series of experiments are performed with an Electron Beam Melting® machine to verify the numerical accuracy. Compared to thermal analysis without considering convection in the molten pool, a closer numerical prediction of geometrical size of molten pool to the experimental data can be achieved by using thermal and fluid flow modeling. The difference between the melt pool geometry in the two models is due to the consideration of the effects of the outward flow in the fluid flow model caused by surface tension.

scholarly journals Understanding the thermal problem of variable gradient functionally graded plate based on hybrid numerical method under linear heat source

2021 ◽  
Vol 13 (5) ◽  
pp. 168781402110178
Author(s):  
Jianhui Tian ◽  
Guoquan Jing ◽  
Xingben Han ◽  
Guangchu Hu ◽  
Shilin Huo
Keyword(s):  
Heat Conduction ◽  
Temperature Distribution ◽  
Heat Source ◽  
Numerical Method ◽  
Functionally Graded ◽  
Thermal Problem ◽  
Linear Heat ◽  
Hybrid Numerical Method ◽  
Linear Heat Source ◽  
Gradient Parameter

The thermal problem of functionally graded materials (FGM) under linear heat source is studied by a hybrid numerical method. The accuracy of the analytical method and the efficiency of the finite element method are taken into account. The volume fraction of FGM in the thickness direction can be changed by changing the gradient parameters. Based on the weighted residual method, the heat conduction equation under the third boundary condition is established. The temperature distribution of FGM under the action of linear heat source is obtained by Fourier transform. The results show that the closer to the heat source it is, the greater the influence of the heat source is and the influence of the heat source is local. The temperature change trend of the observation points is consistent with the heat source, showing a linear change. The results also show that the higher the value of gradient parameter is, the higher the temperature of location point is. The temperature distribution of observation points is positively correlated with gradient parameter. When the gradient parameter value exceeds a certain value, it has a little effect on the temperature change in the model and the heat conduction in the model tends to be pure metal heat conduction, the optimal gradient parameters combined the thermal insulation property of ceramics and the high strength toughness of metals are obtained.

scholarly journals Shape Effect on the Temperature Field during Microwave Heating Process

2018 ◽  
Vol 2018 ◽  
pp. 1-24 ◽  
Author(s):  
Zhijun Zhang ◽  
Tianyi Su ◽  
Shiwei Zhang
Keyword(s):  
Electromagnetic Field ◽  
Heat Conduction ◽  
Temperature Distribution ◽  
Microwave Cavity ◽  
Heating Process ◽  
Shape Effect ◽  
Power Absorption ◽  
Sample Shape ◽  
Distribution Uniformity ◽  
Microwave Process

Aiming at improving the food quality during microwave process, this article mainly focused on the numerical simulation of shape effect, which was evaluated by microwave power absorption capability and temperature distribution uniformity in a single sample heated in a domestic microwave oven. This article only took the electromagnetic field and heat conduction in solid into consideration. The Maxwell equations were used to calculate the distribution of microwave electromagnetic field distribution in the microwave cavity and samples; then the electromagnetic energy was coupled as the heat source in the heat conduction process in samples. Quantitatively, the power absorption capability and temperature distribution uniformity were, respectively, described by power absorption efficiency (PAE) and the statistical variation of coefficient (COV). In addition, we defined the comprehensive evaluation coefficient (CEC) to describe the usability of a specific sample. In accordance with volume or the wave numbers and penetration numbers in the radial and axial directions of samples, they can be classified into different groups. And according to the PAE, COV, and CEC value and the specific need of microwave process, an optimal sample shape and orientation could be decided.

scholarly journals Effects of skin heat conduction on aircraft icing process

2020 ◽  
pp. 095441002097257
Author(s):  
Xiaobin Shen ◽  
Yu Zeng ◽  
Guiping Lin ◽  
Zuodong Mu ◽  
Dongsheng Wen
Keyword(s):  
Heat Conduction ◽  
Temperature Distribution ◽  
Skin Temperature ◽  
Accretion Rate ◽  
Skin Surface ◽  
Ice Thickness ◽  
Ice Accretion ◽  
Aircraft Icing ◽  
Outer Skin ◽  
Lateral Heat

During the aircraft icing process caused by super-cooled droplet impingement, the surface temperature and heat flux distributions of the skin would vary due to the solid substrate heat conduction. An unsteady thermodynamic model of the phase transition was established with a time-implicit solution algorithm, in which the solid heat conduction and the water freezing were analyzed simultaneously. The icing process on a rectangular skin segment was numerically simulated, and the variations of skin temperature distribution, thicknesses of ice layer and water film were obtained. Results show that the presented model could predict the icing process more accurately, and is not sensitive to the selection of time step. The latent heat released by water freezing affects the skin temperature, which in turn changes the icing characteristics. The skin temperature distribution would be affected notably by the boundary condition of the inner skin surface, the lateral heat conduction and thermal property of the skin. It was found that the ice accretion rate of the case that the inner surface boundary is in natural convection at ambient temperature is much smaller than that with constant ambient temperature there; due to the skin lateral heat conduction, the outer skin surface temperature increases first and then decreases with uneven distribution, leading to an unsteady ice accretion rate and uneven ice thickness distribution; a smaller heat conductivity would lead to a more uneven temperature distribution and a lower ice accretion rate in most regions, but the maximum ice thickness could be larger than that of higher heat conductivity skin. Therefore, in order to predict the aircraft icing phenomenon more accurately, it is necessary to consider the solid heat conduction and the boundary conditions of the skin substrate, instead of applying a simple boundary condition of adiabatic or a fixed temperature for the outer skin surface.

Accurate cars measurement and fluid-flow modelling of the temperature distribution around a linear incandescent filament

1986 ◽  
Vol 129 (2) ◽  
pp. 191-196 ◽  
Author(s):  
R. Devonshire ◽  
I.S. Bring ◽  
G. Hoey ◽  
F.M. Porter ◽  
D.R. Williams ◽  
...  
Keyword(s):  
Fluid Flow ◽  
Temperature Distribution ◽  
Flow Modelling
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