Aerostatic thrust bearing — simple orifice restrictor

Load capacity, stiffness, mass flow and orifice sizing for an aerostatic thrust bearing with a simple orifice restrictor. Unlocked from the legacy demo gate; general in its geometry.

✓ validated against legacyoriginal: /calculators/c12_4b2.htm

Outer diameter, D₀mmFeed circle diameter, D₁mmFilm thickness, h₀µmSupply pressure, pₛMPaAmbient pressure, pₐMPaDesign pressure ratio, βPermeability coefficient, kₚ1e-15

Load capacity, F91 N

Load coefficient, F̄0.181

Stiffness, S23 N/µm

Mass flow term, ṁ0.99 mg/s

Volume flow, Q0.05 l/min

Squeeze/permeability number, σ0.563

Effective area ratio, F̄/β0.302

Recess pressure (perturbed), pᵣ0.34 MPa

Unlocked from the legacy "please login" gate. The gate only froze the geometry; the formula is faithful and now works for any bearing size, film and pressure ratio.

Method & references

Aerostatic thrust bearing with a simple orifice restrictor (permeability form).
Load from numerical integration of the radial pressure profile; stiffness by finite difference.
The original demo lock was removed; the formula itself is unchanged and general.

The computation is a literal port of the original client-side JavaScript from /calculators/c12_4b2.htm. Results are verified equal to the original by an automated golden-master test. No formula has been re-derived or “improved”.