How do I install the Xfoil Analysis skill?

Run npx skillmds@latest add ashfordeou/xfoil-analysis in your terminal (requires Node.js), paste this page's agent-chat prompt into Claude, Cursor, or any MCP-connected agent, or download the SKILL.md file and copy it into your agent's skills directory.

Is Xfoil Analysis safe to use?

This skill has not completed SkillMD's automated safety review yet. SkillMD never runs a skill's scripts for you; review the SKILL.md before installing.

Which AI agents work with Xfoil Analysis?

This skill is tagged as working with Claude Code, Claude.ai, OpenAI Codex. SKILL.md is an open format, so most agents that read a skills directory can load it too.

Is Xfoil Analysis free to use?

Yes. Installing skills from SkillMD is free. This skill is licensed under Apache-2.

Who published Xfoil Analysis?

ashfordeOU (@ashfordeou) published this skill. Their other Agent Skills are listed on their SkillMD profile.

Xfoil Analysis by ashfordeou — Agent Skill

Name: Xfoil Analysis
Author: ashfordeOU

Xfoil Analysis

Use when running XFOIL-style airfoil analysis for a given section: plan viscous and inviscid polar runs, validate lift and drag coefficient points against physical plausibility bands, and check NACA 0012 results at Reynolds number 6 million against the classic wind-tunnel anchor (lift coefficient about 0.82 at 10 degrees, zero-lift drag about 0.0079). Distinguishes inviscid runs (drag meaningless) from viscous runs and flags high-drag cases needing transition or mesh-density checks. Trigger: xfoil, airfoil, polar, lift coefficient, drag coefficient, naca, viscous analysis, reynolds number, transition.

ashfordeOU 13c105a 3 files · 9.4 KB Updated Sep 17, 2026

File contents

XFOIL Airfoil Polar Analysis (aerodynamics/airfoil/xfoil-analysis)

Use when the task is airfoil section analysis with XFOIL-style tools: polar run planning, polar-point plausibility checks, and validation against classic airfoil data.

Domain quick reference

XFOIL is a panel-method airfoil analysis tool: inviscid (potential-flow) mode plus an integral boundary-layer coupling for viscous analysis with free or forced transition.
Reynolds number scales the viscous solution; typical validation runs use Re = 6e6.
Classic anchor (NACA Report 824, brief 05 item 7): NACA 0012 at Re = 6e6 gives cl about 0.82 at 10 degrees angle of attack and zero-lift drag coefficient cd0 about 0.0079.
Inviscid XFOIL runs return drag values that are not meaningful; drag requires the viscous analysis.
Polar plausibility bands: alpha in [-25, 30] degrees, cl in [-2.5, 2.5], cd in [0, 0.2].

Workflow

Set the airfoil coordinates, Reynolds number, and Mach number for the polar.
Plan viscous runs (with transition) for drag; treat inviscid runs as lift-only scouting.
Run the polar and validate each point structurally with scripts/xfoil_analysis_logic.py.
Check NACA 0012 at Re = 6e6 results against the anchor bands (cl at 10 deg 0.77-0.87, cd0 0.0069-0.0089).
Use the drag hints (inviscid-run or high-drag) to decide on reruns with transition and finer mesh.

Pitfalls

Quoting inviscid drag as a real result.
cd0 near zero reported without rerunning viscous analysis.
High cd0 blamed on the airfoil before checking transition settings and mesh density.
Validation against the anchor without matching Re = 6e6.

Behavior contract (gate 3)

The polar plausibility, validation, and anchor-check logic is exercised by the gate 3 contract test: scripts/test_xfoil_analysis.py against scripts/xfoil_analysis_logic.py (stdlib unittest, offline). Run: python3 scripts/test_xfoil_analysis.py

Compliance

NACA Report 824 is US government work (public domain); summary and physics values only, per standards-map.yaml.
compliance: STANDARDS-REF, gated: false.

---name: xfoil-analysisdescription: Use when running XFOIL-style airfoil analysis for a given section: plan viscous and inviscid polar runs, validate lift and drag coefficient points against physical plausibility bands, and check NACA 0012 results at Reynolds number 6 million against the classic wind-tunnel anchor (lift coefficient about 0.82 at 10 degrees, zero-lift drag about 0.0079). Distinguishes inviscid runs (drag meaningless) from viscous runs and flags high-drag cases needing transition or mesh-density checks. Trigger: xfoil, airfoil, polar, lift coefficient, drag coefficient, naca, viscous analysis, reynolds number, transition.license: Apache-2.0---# XFOIL Airfoil Polar Analysis (aerodynamics/airfoil/xfoil-analysis)Use when the task is airfoil section analysis with XFOIL-styletools: polar run planning, polar-point plausibility checks, andvalidation against classic airfoil data.## Domain quick reference- XFOIL is a panel-method airfoil analysis tool: inviscid (potential-flow) mode plus an integral boundary-layer coupling for viscous analysis with free or forced transition.- Reynolds number scales the viscous solution; typical validation runs use Re = 6e6.- Classic anchor (NACA Report 824, brief 05 item 7): NACA 0012 at Re = 6e6 gives cl about 0.82 at 10 degrees angle of attack and zero-lift drag coefficient cd0 about 0.0079.- Inviscid XFOIL runs return drag values that are not meaningful; drag requires the viscous analysis.- Polar plausibility bands: alpha in [-25, 30] degrees, cl in [-2.5, 2.5], cd in [0, 0.2].## Workflow1. Set the airfoil coordinates, Reynolds number, and Mach number for the polar.2. Plan viscous runs (with transition) for drag; treat inviscid runs as lift-only scouting.3. Run the polar and validate each point structurally with scripts/xfoil_analysis_logic.py.4. Check NACA 0012 at Re = 6e6 results against the anchor bands (cl at 10 deg 0.77-0.87, cd0 0.0069-0.0089).5. Use the drag hints (inviscid-run or high-drag) to decide on reruns with transition and finer mesh.## Pitfalls- Quoting inviscid drag as a real result.- cd0 near zero reported without rerunning viscous analysis.- High cd0 blamed on the airfoil before checking transition settings and mesh density.- Validation against the anchor without matching Re = 6e6.## Behavior contract (gate 3)The polar plausibility, validation, and anchor-check logic isexercised by the gate 3 contract test: scripts/test_xfoil_analysis.pyagainst scripts/xfoil_analysis_logic.py (stdlib unittest, offline).Run:python3 scripts/test_xfoil_analysis.py## Compliance- NACA Report 824 is US government work (public domain); summary and physics values only, per standards-map.yaml.- compliance: STANDARDS-REF, gated: false.

Frequently asked questions