Fig.3.4 gives the shock layer temperature distribution of 3250K at the stagnation point and 3050K at both ends of the shoulder region. This gives a temperature distribution at the shoulder ends as 94% (3050/3250) of the maximum (stagnation point) value. Fig.3.5 gives the wall temperature distribution as a ratio of shoulder end distance (s) to nose radius (Rn) taken from stagnation points. From the prototype design of Orion MPCV heat shield in Fig.3.1, ‘Rn’ is 60mm and‘s’ is 25mm giving ‘s/Rn’ ratio of 0.416 (25/60). Tracing the Tw curve of 5s in Fig.3.5 using ‘s/Rn’ ratio of 0.416 gives an approximate value of 91.6% (1100/1200) of the stagnation point value. There is no shoulder region temperature lower than 90% of the stagnation point temperature by repeating this process for all other curves in Fig.3.5.
However mere looking at the temperature distribution curves in Fig.3.3, tungsten rods of diameters 6mm, 8mm, 10mm, 20mm, and 40mm seem to satisfy the 90% maximum temperature values at the shoulder regions. This is not true due to some individual temperature analysis in Fig.3.6.