*HsealH**®** **Computational Analysis of
Annular Pressure Seals*

**COST: $3,500 Executable + GUI**

The ** hsealh** program
calculates the static and dynamic force performance of cylindrical annular
pressure seals, including textured surfaces such as

1) seal
leakage,

2) friction torque, power dissipation,

3) load capacity (fluid film forces and restoring moments),

4) 16 complex impedance force and moment coefficients due to dynamic journal
center displacements and journal axis rotations. The real and imaginary parts
of the impedances correspond to the stiffness and damping coefficients
evaluated at a specified excitation frequency,

5) stability indicator or whirl frequency ratio for lateral journal motions and
equivalent stiffness at threshold speed of instability.

for isothermal flow with barotropic fluid **(liquid or gas)** in the single phase
flow regime as a function of

a) rotor (journal) center eccentricity and journal axis misalignment,

b) inlet specified circumferential pre-swirl velocity distribution.

and the following fluids:

(5) water, (6) oil, (7) gas, (12) barotropic liquid
(properties a function of pressure solely)

The ** axial
clearance functions** included are of the type: a) uniform, b) tapered,
c) stepped, or, d) arbitrary via spline
interpolation.

** Analysis:** The motion of a
fluid on the thin film land region of an annular seal is described by mass and
momentum tranport equations (with fluid inertia
effects) with an inertial entrance pressure drop at the seal inlet. Zeroth-order equations describe the fluid flow field for a
rotor static equilibrium position, while first-order (linear) equations govern
the fluid flow for small amplitude rotor center translational and angular
motions. Solution to the zeroth-order flow field
equations provides the seal flow rate, load capacity, and drag torque. Solution
to the first-order equations determines the rotordynamic force and moment
coefficients due to rotor lateral and angular motions.

** Numerical
method of solution:** Control volume - finite difference (SIMPLEC) method.

__Limitations
and Restrictions__** : **Isothermal flows.

** Input**- MS Excel®
interface - worksheet

** Output** - Excel®
interface - worksheet

** Language:** FORTRAN77
Source code NOT provided.

** Users**: Qualiseal, Snecma-SEP,
Exxon-Mobil RC, BP, RAMGEN, Knight-Hawk, ATG, Turbomachinery Research
Consortium members.