The scarce core
Gas Bearings
Aerostatic (orifice, slot-fed and porous), spiral-groove and narrow-groove gas bearings — plus the closely related hydrostatic (liquid-film) bearings. This is the material with the fewest alternatives anywhere — there is no free calculator for spiral-groove bearings elsewhere, and general bearing suites do not cover aerostatic design.
Gas bearing design sits at the specialist end of precision engineering. The theory for spiral-groove bearings traces back to Muijderman’s narrow-groove work (Philips Research Reports, 1964); the aerostatic calculators here encode design relations that are otherwise scattered across out-of-print sources.
All 22 scarce aerostatic/gas- and spiral-groove-bearing models are migrated and validated against the original — this is the part of the migration that got the most care. The 5 hydrostatic-bearing calculators shown below are semi-scarce rather than scarce (a handful of alternatives exist), but sit in the same externally-pressurized-film family.