Hydrodynamic journal bearing
Sommerfeld number, attitude angle, friction, load capacity, stiffness, side leakage and frictional heating for a finite-length hydrodynamic journal bearing. Unlocked from the legacy demo gate; general in shaft diameter, clearance and film thickness.
Load capacity, F9.164 1e3 N
Stiffness, S = -dF/dh3701 1e6 N/m
Power loss6.9 W
Side leakage, Q0.342 1e-6 m³/s
Frictional heating, ΔT13.2 K
Bearing length number, L/D1
Clearance number, R/ΔR1000
Eccentricity ratio, ε = (ΔR-h₀)/ΔR0.85
Sommerfeld number, So9.116
Attitude angle, β37.4 deg
Flow number, Cq0.68
Friction number, µ(R/ΔR)1.199
Coefficient of friction, µ0.0012
Unlocked from the legacy "please login" gate on D/ΔD/h₀. The gate only froze those three inputs; the formula uses them solely via the derived R, dR_R, L_D and eps with no second hardcoded literal, so it is faithfully general for any bearing geometry (see header comment).
Method & references
- Hydrodynamic journal bearing, finite length, Sommerfeld/short-bearing interpolation.
- Stiffness by finite difference on a 0.1% eccentricity perturbation.
The computation is a literal port of the original client-side JavaScript from /calculators/c9_3.htm. Results are verified equal to the original by an automated golden-master test. No formula has been re-derived or “improved”.