VIC polars in HENFOIL — what they are and are not

Production polars for selection

Selection needs polars you can repeat under the same assumptions. HENFOIL uses VIC (viscous-inviscid coupling) as the production polar engine for multi-point curves, envelopes and batch runs.

What VIC is good for

• Early section ranking across candidates
• Cruise / climb / robustness envelopes
• Sensitivity to Reynolds number and transition assumptions
• Documenting why candidate A beat candidate B in weighted compare
• Feeding inverse and optimize loops with a consistent polar definition

Method IDs sit on calculated CL, CD and Cm so the trail is auditable.

What VIC is not

• A wind-tunnel campaign
• An XFOIL marketing clone claim
• A flight-Re wall-resolved RANS certificate
• A substitute for certification airloads

When the program needs those, you take the HENFOIL selection package into the next tool. You do not pretend VIC already was that tool.

Envelopes and batch

Envelopes capture mission-weighted behaviour, not a single peak CL. Batch runs evaluate many sections or conditions without hand-clicking every case; async jobs keep large sets off the interactive loop.

Honesty on the plot

The plot is only as honest as the label. HENFOIL keeps VIC labelled as VIC. That is how teams move faster without overclaiming in design review.

In simple words: what this page is for

VIC is the production polar engine for compare and select. Deep notes on use cases, limits, envelopes and honesty labels.

This lesson exists because section decisions fail when geometry, method labels and selection reasons are scattered. VIC polars in HENFOIL — what they are and are not helps you keep a clean trail from shape to polar to choice.

Why the topic matters

Engineers lose time when a title sounds clear but the page only sketches the idea. This article expands VIC polars in HENFOIL — what they are and are not so you can answer three questions without jargon: what is the idea, when do you use it, and how do you check it in a HENDOI product.

Read the sections above for the core definitions. Use the steps below to move from reading into a real project trail you can share with a teammate.

How to apply this in HENDOI

In practice: create a HENDOI account or log in, open HENFOIL, bring a section in (create, import DAT, or digitize), pass the geometry gate, climb the analysis ladder only as far as the decision needs, then compare and archive. Every calculated number should keep its method label.

When the section choice is ready for the aircraft, continue in HENSYNTH for mission, compliance and trades. Same account. Same plans.

What this page will not claim: a teaching polar or geometry note is not a flight-Re certificate. HENFOIL labels methods so you know what you bought. Tunnel data and professional judgement still sit outside any single software run.

Checklist before you leave this page

• Can you state the idea of VIC polars in HENFOIL — what they are and are not in one sentence?
• Do you know which product owns the next action — HENFOIL or HENSYNTH?
• Will every number you keep carry a method label or a stored-run source?
• If you are new here, have you opened Register or Login?

Related reading on this site

• Airfoil selection with a documented why-#1
• The HENFOIL analysis ladder: when to escalate
• Create airfoil fields: NACA, analytic and CST — what each digit means
• Digitize field-by-field: every control, why fill it, what you get
• All HENDOI blog articles
• HENFOIL product page
• HENSYNTH product page
• Pricing — Student, Professional & Team
• FAQ
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