Hi everyone, This project shows an FEA thermal analysis of a thermal shipper pack for a temperature vs time profile without the need for conjugate heat transfer analysis.
A realistic industry thermal shipper package design is considered for the simulation. It was created in OnShape and it is shown in the pictures below:
To simplify the geometry, only 1/4 of the model was used for the analysis like shown in the image below:
In this shipper design, temperature is passively controlled by pre-conditioned frozen (-20°C) ad liquid (5°C) refrigerants in combination with an insulated polyurethane (PUR) foam container (with inner product box). The temperature inside the Payload area at the end of the temperature vs time profile must remain between 2°C and 8°C.
A tet-dominated meshing algorithm is used to mesh the entire geometry. An automatic operation was performed with a moderate mesh fineness. The figure below shows the meshed geometry:
A nonlinear transient heat transfer analysis type is selected to compute the temperature distribution on the entire body.
All the contacts were made as bonded contacts. With the actual model was needed 6 pairs of contacts containing several faces which were grouped into topological entity sets.
The material properties were set considering densities, specific heat capacity (cp) and thermal conductivity (k). For the PCMs, cp and k were set considering also the values below ad above the phase change temperature.
The boundary condition is then setup with a convective heat flux applied on the outer surfaces of the shipper like in the image below:
The heat flux follows a temperature vs time CSV file which correspond to a summer 96 hours temperature profile.
The temperature distribution and the temperature vs time for 3 internal payload points are visualised:
I downloaded the graphs for the temperature results for each point data and also the temperature vs time profile and have grouped all of them into only one graph as shown below:
From the shipper product load temperature vs time graph, we can see that the temperatures monitored inside the payload area remained between 2°C and 8°C which was the main goal of this analysis.
Also a GIF animation showing the temperature distribution during the 96 hours is shown below:
The final temperature distribution is also plotted with the mesh:
The simulation has shown that, with the given 96 hours profile, the temperature profile versus time of this PUR shipper can be accurately simulated using conduction approach.
A new analysis can be done for a winter temperature profile simply by uploading a new temperature curve in the heat flux definition.