First-pass
Fast setup, early trades, and quick sensitivity checks.
Solve Workflow
A target design point is not always the balanced operating point.
First-pass sizing answers “what design matches these inputs?” Coupled steady-state solving asks how the injector, throat, feed boundary, thermochemistry path, and nozzle settle together for a modeled operating point.
Updated June 12, 2026.
Use first-pass sizing for speed.
First-pass mode is useful when a team is still shaping the design space. It lets engineers move quickly through chamber targets, O/F choices, nozzle geometry, and injector concepts without pretending that every downstream coupling has been resolved.
Use coupled solving for consistency checks.
Coupled steady-state solving is a stronger review surface when injector geometry, feed boundary assumptions, throat area, and thermochemistry all matter together. It remains a steady-state model, not a full start transient or final test prediction.
Coupled steady-state
Operating-point consistency across injector, throat, feed boundary, and nozzle assumptions.
Review outputs
Warnings, reports, and exports tied to the same solved case.
Boundary
Neither mode is a replacement for transient feed-line analysis, combustion stability work, CFD, hot-fire data, or formal qualification. The value is traceable iteration before those higher-cost steps.