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
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.