: For steam ejectors, these include specific constants (often labeled A through J) derived from industry standards like those by Al Dessouky or Hisham Ettouney.
| Issue | Impact | |-------|--------| | | Errors with wet steam or non-ideal gases | | Assumes perfect mixing | Overestimates performance | | No shock wave model | Cannot predict double-choking behavior | | 1D only | Misses 2D/3D losses | | No off-design prediction | Only works at design point | | Poor validation | Most free spreadsheets are not tested against real data | Ejector Calculation Excel
: Summary tables showing the required steam consumption and expected performance curves. 3. Adding Advanced Functionality : For steam ejectors, these include specific constants
| Criterion | Points (0–5) | |-----------|--------------| | Clear inputs | 5 | | Uses real fluid properties | 3 | | Checks choking in nozzle & diffuser | 4 | | Handles off-design | 1 | | Includes validation example | 2 | | Units flexible | 4 | | No hidden errors | 2 | | | ~3/10 | Adding Advanced Functionality | Criterion | Points (0–5)
The process starts by defining the physical equations required to model ejector performance. For steam ejectors, this typically involves semi-empirical correlations for the —the ratio of entrained mass flow to motive steam flow. Motive Stream : High-pressure steam used to create a vacuum.