Content | Measurement parameters | Experimental results | Comparison with simulation


 Measurement parameters

Temperature measurements at stop were performed to do a comparison with numerical results.

The following parameters were taken:

The inlet temperature was 35°C

The velocity was estimated at 1 m/s.

Only the main windshields were turned on.

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 Results

The following graph shows the evolution of the temperature on front seats:

About 2 minutes are required to observe a increase of 0.5°C. Then the temperature increase is almost linear.

Others measurements at different points lead to the same observations.

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 Comparison with simulation

The simulations of this case do not give this evolution: the temperature increases very quickly.

The reason is that our model does not take into account heat losses and thermal features of most of the passenger compartment. Improving boundary conditions seems to be the key to reach to more realistic results.

The following pictures represent the results of the simulation after 38 seconds:

We cansee on this picture that the increasement of temperature on the front seats is about 5 K. It does not correspond to reality.

The following picture shos the isovalue curve of temperature at 295 K. It also shows that the heating is too quick in the cabin.

Finally, the study of the computed path lines show the great problem of our model: the boundary condition at the outlet: the flow goes out at only two localised zones in the cabin, which does not correspond to reality:

The conclusion of this comparison is therefore that our modelization is not good.

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