Space environments: DSMC/CFD plume modeling and multiphysics interactions

The situation

Space systems operate where intuition can fail: rarefied flows, plume impingement, contamination risk, and complex thermal coupling. Testing is limited, and conservative margins can be costly.

Why it matters

Without defensible performance understanding, teams risk:

• Mission risk from unmodeled plume-surface interactions
• Overly conservative design that increases mass and cost
• Late-stage integration issues with sensors, optics, or thermal control
• Surprises that are expensive or impossible to correct post-launch

What analysis changes

A focused simulation study can help answer decision-level questions such as:

• Characterize plume expansion and impingement trends
• Identify sensitive orientations and operational envelopes
• Evaluate thermal/force impacts at decision-relevant fidelity
• Produce defensible rationale for design and operations constraints

Typical approach

1. Define the decision: acceptable envelope, component placement, or operational constraints.
2. Select the right method (DSMC vs. continuum CFD vs. hybrid) based on regime.
3. Run targeted cases to map worst-case behaviors and sensitivities.
4. Summarize conclusions in decision-ready guidance.

Deliverables

• Plume interaction characterization (trends + sensitivities)
• Surface impact estimates at appropriate fidelity
• Documented assumptions and uncertainty bounds
• Operational recommendations / design constraints

Common pitfalls

• Using continuum methods outside validity without stating limitations
• Treating one case as worst-case without bounding parameters
• Missing coupling pathways (thermal, contamination, forces)