Air bearing, porous surface feed — fixed reference geometry
Reference-geometry calculator (Ø40mm outer diameter, 5µm film, β=0.6 — fixed) for an aerostatic thrust bearing fed through a porous surface (permeability-coefficient restriction).
Load capacity, F185 N
Stiffness, S42.5 N/µm
Mass flow, ṁ3.29 mg/s
Volume flow, Q0.166 l/min
Squeeze/permeability number, σ3.176
Perturbed recess pressure, pᵣ0.34034 MPa
The legacy "please login" demo lock froze D0/H0/B1. The film thickness is additionally hardcoded (5e-6) directly inside the mass-flow formula, so this is kept as a fixed-geometry reference calculator. Only the inputs that were already free under the lock are exposed.
Method & references
- Aerostatic thrust bearing fed through a porous surface (permeability-based restriction).
- FIXED GEOMETRY: outer diameter 40 mm, film 5 µm, β=0.6 — the film thickness is also hardcoded directly in the mass-flow formula, not only via the demo lock.
- Generalizing the outer radius/film is a real model change and is not done here — see docs/locked-calculators-review.md.
The computation is a literal port of the original client-side JavaScript from /calculators/c12_4d.htm. Results are verified equal to the original by an automated golden-master test. No formula has been re-derived or “improved”.