Simulated Transient Evolutionary Plume Signature (STEPS)

Nonsteady plume signatures can result from transient engine operating conditions (e.g., start-up, shut-down) or evolutionary vehicle flight conditions (acceleration, ascent). Current standard plume signature codes assume constant engine/flight conditions as for a steady engine burn in a ground static test. An advanced simulation capability is proposed that enables time-continuous multi-scale nonsteady plume signatures for transient/evolutionary engine/flight conditions throughout and beyond the boost phase. The nonsteady simulation tool incorporates rigorous first-principles physical models and efficient stable numerical methods adopted from an existing steady-state simulation tool. The simulation uses a natural coordinate grid that is coupled to the flow and determined simultaneously; the flow and grid to evolve together in space and time from chamber-to-trail and ground-to-space. The extension to nonsteady flows enables enhanced physical realism in time-accurate computations to support improved fidelity and speed in real-time dynamic engagement simulations.