CALCULATORS / AERODYNAMICS AND FLIGHT SCREENING

Aerodynamic lift calculator

Lift at supplied constant coefficient; no stall or compressibility model.

aerodynamics-lift.napkin / editable

SCENARIO COMPARISON

Compare the numbers.

This source describes an analytical model. Its quantities and checks are the view.

Scenario	liftN
	55.125
	44.1

All calculated quantities are listed with the inputs. Switch to Source to inspect the equations.

SCENARIOS / CALCULATED VALUESSAME SOURCE

Change an input to see the consequences.

lift target55.13 N✓ passes

BASELINE INPUTS

density1.225 kg/m^3speed15 m/sarea0.5 m^2coefficient0.8

CALCULATED

lift55.125 N

Edits change the baseline source.

THE SOURCE

Edits below update the same model.

# Aerodynamic lift
# Scope: Lift at supplied constant coefficient; no stall or compressibility model.
# Status: illustrative worked example; engineering review pending.
# Inputs are example values. Checks are editable example requirements, not standards.

density = 1.225 kg/m^3
speed = 15 m/s
area = 0.5 m^2
coefficient = 0.8

lift := density*speed^2*area*coefficient/2 [N]

check lift target: lift >= 50 N

scenario alternative: density = 0.98 kg/m^3

Calculated from your source · not saved

Baseline · Baseline

lift target55.13 N ✓ passes

alternative · alternative

lift target44.10 N × fails

Illustrative first-order example. Checks are editable requirements, not design standards. The broader topic may require additional equations, data, and validation.

Formula and units

This example uses the following equations. Input names and units match the editable source above.

lift: lift = density*speed^2*area*coefficient/2 [N]

Original worked example

These are the baseline values in the downloadable source. Edits above let you test your own values.

Given

density: 1.225 kg/m^3
speed: 15 m/s
area: 0.5 m^2
coefficient: 0.8

Calculated

lift: 55.125 N

Assumptions and limits

Lift at supplied constant coefficient; no stall or compressibility model.

The requirement checks use the limits written in this example. Passing a check does not establish that the model covers every load, material behavior, or operating condition in a real design.

Download this .napkin example ↓

Take it further with your agent

Napkin keeps the inputs, equations, checks and assumptions together in one study. Your agent sets it up; you change the numbers.

Try with Claude ↗

codex 'Use Napkin (https://napkin.engineering/mcp, or the local Napkin plugin) to build a study: Aerodynamic lift. Inputs: density; speed; wing area; lift coefficient. Outputs: lift; required speed or area. Model scope: Coefficient-based models over an explicitly limited flight regime. Read napkin_capabilities and the current snapshot. Ask me for the values that matter, label assumptions with units, author .napkin source, validate it and apply it with napkin_source using the current revision, then open the study. Add checks for the limits I supply. Keep unsupported analyses explicit.'

Claude needs the Napkin connector; Codex needs the Napkin plugin. Set up your agent ↗

The broader study

The topic brief below describes the broader scope. The worked example above states the particular calculation it implements.

Inputs: density, speed, wing area, lift coefficient
Outputs: lift, required speed or area
Modes: calculate, compare, sweep
Drawing: Force and flight-envelope plots

EXECUTABLE WORKED EXAMPLE · FIRST-ORDER MODEL · CHECK THE SCOPE & ASSUMPTIONS