2. Benchmark solution#

2.1. Calculation method used for the reference solution#

\(T(x,y,t)=\sum _{n=1}^{\infty }\sum _{j=1}^{\infty }{A}_{n}\mathrm{sin}\frac{n\pi x}{{L}_{x}}\mathrm{sin}\frac{j\pi y}{{L}_{y}}\mathrm{exp}\left[-(\frac{{\lambda }_{x}{n}^{2}{\pi }^{2}}{{L}_{x}^{2}}+\frac{{\lambda }_{y}{j}^{2}{\pi }^{2}}{{L}_{y}^{2}})t/\rho c\right]\)

where \({A}_{n}=\left[\frac{4({T}_{i})}{{\pi }^{2}jn}[{(-1)}^{n}-1][{(-1)}^{j}-1]-32\right]\frac{5}{9}\) \({T}_{i}=\frac{5}{9}{T}_{0}+32\)

Temperature in \(°C\) to \(t=\mathrm{4320s}\)

3.0

-17.7778

-17.5742

-17.3905

-17.2448

-17.1515

-17.1189

2.7

-17.7778

-17.5764

-17.3948

-17.2507

-17.1581

-17.1262

2.4

-17.7778

-17.5832

-17.4077

-17.2684

-17.1790

-17.1482

2.1

-17.7778

-17.5945

-17.4291

-17.2979

-17.2137

-17.1847

1.8

-17.7778

-17.6102

-17.4590

-17.3391

-17.2620

-17.2355

1.5

-17.7778

-17.6302

-17.4970

-17.3914

-17.3235

-17.3002

1.2

-17.7778

-17.6542

-17.5426

-17.4541

-17.3973

-17.3777

0.9

-17.7778

-17.6816

-17.5949

-17.5261

-17.4819

-17.4667

0.6

-17.7778

-17.7120

-17.6526

-17.6056

-17.5753

-17.5649

0.3

-17.7778

-17.7444

-17.7142

-17.6903

-17.6749

-17.6696

0.0

-17.7778

-17.7778

-17.7778

-17.7778

-17.7778

-17.7778

\(Y\uparrow\) \(X\to\)

0.0

0.3

0.6

0.9

1.2

1.5

Reference values are obtained with \(n=j=1000\)

2.2. Benchmark results#

\(t=4\mathrm{320s}(\mathrm{1.2hr})\): temperature at the following points:

  • in \(x=0.6\): for \(y=0.6,1.5,2.4,3.0\)

  • in \(x=1.5\): for \(y=0.6,1.5,2.4,3.0\)

2.3. Uncertainty about the solution#

Analytical solution.

2.4. Bibliographical references#

  1. J.C. Bruch Jr., G. Zyroloski, “Transient two-dimensional heat conduction problems solved by the finite element method”, Int. J. num. Meth. Engng, vol. 8, no. 3, pp 481-494, 1974.