THRUST
Brochure
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LTSQAP [PC]
This program employs the least squares method for error balancing
based on the calculation of system influence coefficients. It can
handle up to 5 unbalance planes, 10 speeds, 10 probes and accounts
for residual run-out or shaft bow. ROMAC Report No. 71.
DAMBRG2 [PC]
DAMBRG2 calculates dynamic coefficients, power losses, and rigid
rotor stability information for two-lobe isoviscous bearings with a
pressure dam in only one pad. Opposite to the dam the user may
specify the presence of a track. The code solves the two-dimensional
Reynolds Equation including an optional linearized turbulence model.
ROMAC Report No. 97.
PDAM2D [PC]
A multiple pad pressure dam bearing can be analyzed by this program.
The geometry of each pad can be different as specified by the user.
It calculates the journal equilibrium position, linearized stiffness
and damping coefficients, and rigid rotor stability threshold. The
full two dimensional Reynolds equation is solved for each pad. This
program is an extension of DAMBRG2 which solves for a bearing with a
single pressure dam. ROMAC Report No. 228.
SQFDAMP [PC]
This program determines stiffness and damping coefficients for short
and long squeeze film bearings with and without fluid film
cavitation. ROMAC Report No. 11.
THBRG [UNIX & PC]
THBRG calculates the pressure profiles, temperature distribution in
film and bearing housing, lubricant flow rates, power loss, and
dynamic coefficients for a multilobe journal bearing with an
incompressible lubricant. A combination of finite element and finite
difference methods are used to solve the governing equations. THBRG
uses an assumed axial pressure profile and an assumed cross-film
viscosity variation to decrease the dimensionality of the problem to
the circumferential direction only. This significantly increases the
speed of the program while retaining high accuracy. The analysis
includes fluid film conduction, cross-film viscosity variation,
two-phase cavitation models for the energy equation, conduction in
the housing, convection heat transfer from housing and turbulence.
ROMAC Report No. 273.
THPAD [PC]
THPAD calculates the pressure profiles, temperature distribution in
film and bearing components, lubricant flow rates, power loss, and
dynamic coefficients for a tilting pad journal bearing with an
incompressible lubricant. A combination of finite element and finite
difference methods are used to solve the governing equations. THPAD
uses an assumed axial pressure profile and an assumed cross-film
viscosity variation to decrease the dimensionality of the problem to
the circumferential direction only. This significantly increases the
speed of the program while retaining high accuracy. The analysis
includes pad mechanical and thermal deformations, journal thermal
deformation, fluid film conduction, cross-film viscosity variation,
pivot deformation, two-phase cavitation models for the energy
equation, and turbulence. ROMAC Report No. 284.
THRUST [UNIX & PC]
THRUST predicts the steady-state operating characteristics of
tilting-pad and fixed geomety fluid-film thrust bearings. The
operating characteristics predicted by the program include the film
thickness distribution, film temperature distribution, pad and runner
temperature distribution, power losses, flow requirements, and pad
and runner elastic deformation. The analysis includes effects due to
cavitation, turbulence, cross-film viscosity variation, centrifugal
inertia, temperature and pressure dependent viscosity, crowns, and
detailed pad models. The beta version has been released. ROMAC Report
No. 376.
CRTSP2 [PC]
CRTSP2 calculates the undamped planar critical speeds of dual-level
rotor systems using the transfer matrix method. The method includes
rotary inertia, shear deformation, circularly symmetric gyroscopic,
and lumped inertia effects. Both translational and rotational springs
may couple the rotors or tie the rotors to ground. Rotor model and
modeshape plots are possible. A critical speed plot may also be
produced if more than one bearing configuration is considered. CRTSP2
may be used to produce the modal input for other codes such as FRESP2
and COTRAN. ROMAC Report Nos. 60 and 103.
MODFR2 [PC]
MODFR2 is used to determine the undamped planar critical speeds of
single or dual level rotor systems using the finite element modeling
method. The approach includes rotary inertia, lumped inertia effects,
translational and rotational springs, lumped and consistent mass
options, but does not include gyroscopic effects. MODFR2 can be run
with or without coupling the rotor system to ground and, therefore,
is ideally suited to producing the modal input for other codes such
as FRESP2 and COTRAN. ROMAC Report No. 291.
TWIST2 [UNIX & PC]
Program TWIST2 calculates the undamped torsional natural frequencies
and mode shapes for single shafts, geared shafting with branching, or
looped systems. The finite element method is used to obtain the set
of equations governing the motion of the system. The program also
determines the steady-state forced response characteristics of the
system from harmonic torsional input using modal analysis. In the
forced response calculations, damping may be added to the system
through modal damping ratios or discrete dampers. The input torque
magnitudes and phases may be specified as a function of excitation
frequency. In addition, several modeling features such as disk models
and the "degree rule" are included. ROMAC Report No. 290.
FRESP2 [PC]
This program is a modal frequency response program for analyzing the
forced response of a dual rotor system with flexible substructure.
The program allows the user to analyze a system with unbalance or
generalized forces on the rotor, or general forces, displacements, or
accelerations applied to the substructure. Generalized speed
dependent coupling coefficients are used to represent bearings,
seals, and aerodynamic cross-couplings. ROMAC Report Nos. 210 and
218. (Report 210 is the program user's manual, 218 is the program
listing.)
RESP2V3 [PC]
This program calculates the non-planar synchronous unbalance response
of dual-level multimass flexible rotors (or rotors with flexible
casing) using a transfer matrix approach. The modeling includes
gyroscopic, rotary inertia, shear deformation, and hysteretic damping
effects. Speed-dependent linearized bearing coefficients (with linear
interpolation by the program as needed) are supported. ROMAC Report
No. 81.
HCOMB [PC]
This program solves the bulk-flow equations for the adiabatic flow of
a compressible gas within a straight-through honeycomb seal. It
calculates the leakage and the dynamic coefficients. ROMAC Report No.
425.
LABY3 [UNIX & PC]
LABY3 calculates the leakage flow and dynamic coefficients for
compressible fluid straight-through and uniform interlocking type
labyrinth seals. Teeth may be specified on the rotor, stator, or
both. The method of Iwatsubo, as improved by Childs, is used as the
theoretical basis. ROMAC Report No. 344.
SEAL2 [UNIX & PC]
This program calculates steady state load capacity, stiffness and
damping coefficients for plain and grooved seals with incompressible
turbulent axial flow. (New Version 1.2.) ROMAC Report Nos. 191 and
194.
SEAL3 [PC]
This program uses a bulk fluid flow perturbation analysis to evaluate
rotor dynamic coefficients for stiffness, damping and mass
coefficients. It can analyze both plain and circumferentially grooved
seals. It adds inlet swirl, mass coefficients and surface roughness.
ROMAC Report No. 418.
TURSEAL [UNIX & PC]
This program calculates the stiffness and damping coefficients of
turbulent flow annular seals or water lubricated bearings using
finite elements. Finite length seals and variable circumferential and
axial Reynolds numbers are considered. Turbulence coefficients based
on the data of Elrod and Ng are utilized through curve fits. The
program has also been found to work well for laminar flow. ROMAC
Report No. 145.
FSTB3 [UNIX & PC]
This program calculates the stability, damped critical speeds
(eigenvalues), and elliptical whirl mode shapes for multi-spool rotor
systems. Linearized fixed geometry bearing coefficients, linearized
complete tilting-pad bearing models, and/or linearized
collocated/non-collocated magnetic bearing models in the form of
transfer functions may be used as rotor support mechanisms. The
program includes gyroscopic, rotary inertia, shear deformation, and
aerodynamic cross-coupling models. ROMAC Report Nos. 294 and 295.
ROTSTB [PC]
This program calculates the stability, damped critical speeds
(eigenvalues), and elliptical whirl mode shapes for single spool
rotors. Linearized fixed geometry bearing coefficients, linearized
complete tilting pad bearing models, and/or linearized
collocated/non-collocated magnetic bearing models in the form of
transfer functions are allowed. The program supports flexible support
models with each bearing type. The program uses the transfer matrix
method in non-dimensional form and includes the effects of
gyroscopics, rotary inertia, shear deformation, aerodynamic cross
coupling, and hysteretic damping. Rotor cross-section and damped mode
shape plots are possible. ROMAC Report Nos. 58 and 337.
COTRAN [PC]
Nonlinear time transient program for multi-level rotors with
substructure. Program uses modal input from CRTSP2 or MODFR2 to
create small order inverse mass and stiffness matrices for master
degrees of freedom which are integrated forward in time using
Newmark's method. Nonlinearities include hydrodynamic bearings and
rubs. (Manual provided on disk with code.)
TORTRAN2 [PC]
This program is a computational tool designed to aid in torsional
failure prediction. It computes the following information about the
rotor system: rigid body angular velocity and acceleration; rotor
startup time; transient angular velocity, torque and stress; and,
estimated rotor lifetime. ROMAC Report No. 377.
TORTRAN3 [PC]
TORTRAN3 is a transient response program for torsional rotor systems.
It can analyze rotor systems with non-linear couplings that are
driven by synchronous machines, variable frequency drives, or any
other torsional forcing function that can be expressed as a function
of time or rotor speed. One important feature of TORTRAN3 is its
cumulative fatigue analysis. Rotors that undergo large periodic
loading, such as synchronous motor driven machines during startup,
may fail after a finite number of starts. ROMAC Report No. 399.
ROMAC