Phoenix-1 Test Stand Heating

Background

The Phoenix-1 test stand is essentially a vertical I-beam, with PHX's critical components (tanks, plumbing, engine) bolted on using various fixtures and sensing equipment. Of particular interest to the Structures team is the thrust profile of our engine, which we plan on measuring using 4 load cells above the engine. Load cells tend to have operating temperatures <100*C, and the engine is expected to reach 1000+*C, with internal temperatures exceeding 3000*C. At such temperatures, radiative heat transfer may be significant. I conducted a mixed-mode (conduction and radiation) 20s transient heat transfer study to determine whether or not the load cells would require additional shielding during the duration of the engine's firing.

Conclusions

The load cells are to be placed directly below the plate and above the arms. After 20s, the majority of the arms' length remains below 50*C, indicating adequate thermal conditions for the load cells.

A Look Back

If I were to conduct this study again with no mesh limitations, a lot more work would be put into optimizing the mesh. I would make the overall mesh finer, especially near the bottom of the arms since the temperature gradient is fairly large. I would also create a radial mesh with enough elements through the thickness in the TCA to capture the large thermal gradient through the wall. Unfortunately, most of the BCs are approximations since we did not know too much about the BCs at the time. One major factor that was not modeled is ablation, which this version of the engine relied on. A newer model of the engine is using regenerative cooling, which will likely be a future project.