The horizontal reference lines were not used for maximum temperature
distribution shown in Fig.4.2. The graph shows that tungsten rod of 2mm
diameter attained a steady state temperature of 2420\(^0\)C
at time 22 seconds. Tungsten rod of 4mm diameter just attained a steady
state temperature of 1290\(^0\)C at time 30 seconds. The
6mm, 8mm, and 10mm diameters are yet to attain steady state values.
However, looking at Fig.4.1, it can easily be observed that heat shield
surface temperature of ‘a’ is about 2000K though it is showing a maximum
temperature of 2712K. This implies that upstream of tungsten connection
has higher temperature values meaning 2mm diameter is too small for a
400A current rating. Every other diameter (4mm, 6mm, 8mm, and 10mm) seem
to be geometrically capable. At this point, none of the geometric
representation gives a good replication of re-entry temperature
distribution [3] though Fig.4.1.e seems to be very close by mere
observation.