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An egg with an initial temperature 25C was place into a boiling water for 15 minutes. Heat from the boiling water enters the egg and changes its temperature gradually over time and space. Using the 2 dimensional finite element method, prove that the temperature of the egg varies from the shell to the center of the egg. You may need to develop your own nodes before start deriving the equations.

Respuesta :

It is proved from the below that the temperature of the egg varies from the shell to the center of the egg.

Using the 2-dimensional finite element method, we will need to find the Biot number of the system by using the formula:

[tex]\mathbf{Bi = \dfrac{h_c r_o}{k} }[/tex]

According to the Heisler chart, the curves in the graph represent a range of values for the inverse of the Biot number,

where;

[tex]\mathbf{Bi = \dfrac{h_c r_o}{k} }[/tex]

here;

  • k = the material's thermal conductivity
  • h = the heat transfer coefficient.

By developing nodes based on assumptions;

[tex]\mathbf{Bi = \dfrac{1700 \times 0.025}{0.682} }[/tex]

Bi = 62.32

The inverse of Biot number is:

[tex]\mathbf{=\dfrac{1}{Bi}}[/tex]

[tex]\mathbf{=\dfrac{1}{62.32}}[/tex]

= 0.016

Similarly, the Fourier number [tex]\mathbf{F_o}}[/tex] is calculated by using the expression;

[tex]\mathbf{F_o = \dfrac{\alpha t }{r_o^2} }[/tex]

[tex]\mathbf{F_o = \dfrac{k t }{\rho c_pr_o^2} }[/tex]

where;

  • time (t) = 15 mins = (15 × 60) sec

[tex]\mathbf{F_o = \dfrac{0.682 \times 15 \times 60 }{958.4 \times 4211 \times 0.025^2} }[/tex]

[tex]\mathbf{F_o = 0.243}[/tex]

Using the 2-dimensional finite element method, the temperature ratio is:

[tex]\mathbf{\dfrac{T(0,t) -T_{\infty}}{T_o -T_{\infty}} = 0.1 }[/tex]

T(0,t) = 100 + 0.1(4-100)

T(0,t) = 100 + 0.1(-96)

T(0,t) = 100 - 9.6

T(0, t) = 90.4° C

Therefore, we can conclude that it is proved that the temperature of the egg varies from the shell to the center of the egg.

Learn more about the Heisler chart here:

https://brainly.com/question/14839677?referrer=searchResults

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