FIGURE 4-1 Location of thermocouples (X) and computational fluid dynamics model “cold spots” on test rounds and in tray for June 14 testing. SOURCE: BPBGT, 2007a.

mocouples are in direct contact with only the sheath, which is in contact with the projectile surface. The measurements were taken to be surface temperatures when compared with the CFD predictions. However, the sheath is also in contact with the outside environment and is subject to both direct convective and radiative heating. It is a matter of speculation whether or not the extra heat transported through the outside sheath to the thermocouple lead is significant, but it could lead to erroneous temperature measurements. The preferred method of measuring surface temperature is to feed the thermocouple wires through holes from the inside of the projectile to the surface. Then, the sheath and leads are not exposed to the outside environment.


Finding. Errors may exist in the experimental temperature measurements with thermocouples from heat transfer through the leads.

TEMPERATURE PREDICTION BY COMPUTATIONAL FLUID DYNAMICS THERMAL MODELING

The Bechtel Parsons Blue Grass Team (BPBGT) used a mathematical model for comparison with the TRRP experimental measurements and to predict the performance of the full-scale MPT for the Blue Grass Chemical Agent Destruction Pilot Plant. The BPBGT’s model gives spatial and temporal temperature behavior of the parts being processed in the MPT. The purpose of the modeling was to show that the MPT design was adequate for treating munitions at 1000ºF for 15 minutes while meeting operational and schedule requirements and that the design could guide the scale-up and the testing of the full-size unit.

Comparison with the experimental measurements was used to validate and modify the model. The improved model appears to be fairly rigorous; it uses a commercial CFD package, AcuSolve Version 1.7b (Acusim Inc.), which is a



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