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 HONEYCOMB, round-hole patterns, knurled, etc

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.

Flow model: Fully Developed Laminar, Transition regime, and/or Turbulent Bulk-Flow Model

Governing Equations: Continuity, Circumferential and Axial Bulk-Flow Momentum Equations with inlet inertial pressure losses.

Turbulence Closure Model: Bulk-Flow with friction parameters based on Moody's friction factor equations for roughened surface conditions.

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.