Dyrobes Rotor Dinamik Yazılımı

• Dyrobes Rotordynamics software is capable of analyzing lateral, torsional, and axial vibrations.
• Finite Element Formulation
• Flexible and Rigid Disks
• Flexible Supports and Foundation
• Static Deflection and Bearing/Constraint Reactions
• Critical Speed Analysis
• Critical Speed Map Analysis
• Whirl Speed and Stability Analysis
• Steady State Harmonic Excitation Analysis
• Steady Maneuver Load Analysis
• Time Transient Analysis
• Constant Speed or Speed with Acceleration
• Unbalance, Skew Disks, Shaft Bow, Misalignment, Time Forcing, etc.
• All types of linear and nonlinear bearings and dampers

Dyrobes software has been developed to analyze the bearing steady state and dynamics performance of fixed lobes, pressure dam, multiple pockets, floating ring bushing, flexural pad and tilting pad hydrodynamics journal bearings based on Finite Element Methods. In additional to journal bearing analysis, the program also performs thrust bearing analysis, lubricant properties analysis, and oil flow calculation.

• Many new bearing types have been implemented into BePerf.
• Journal Bearing
• Constant Viscosity, Heat Balance
• Arbitrary Load Vector
• Laminar or Turbulent Model
• Fixed Lobes Bearings
• 3 Lobes and Higher Lobes
• Pressure Dam, Multiple Pockets, Step Bearings
• Taper Land Journal Bearing
• Worn Pocket Bearing, etc.
• Tilting Pad Bearings
• Various Flexible Pivot Configuration
• Load on Pivot, Between Pivots, Arbitrary Pivot location
• Multiple Preloads
• Floating Ring Bushing
• Ring/Shaft Speed Ratio can be calculated internally or specified
• Gas bearing

This program calculates the bearing loads due to gear power transmission and aero thrust forces. The gears can be spur gears, helical gears, or double helical gears (herringbone gears). Applications include integrally geared compressors, blowers, pumps, and expanders, etc. Typical compressor system configuration includes a driver unit (motor, engine, turbine, etc.), which drives several high-speed shafts (driven units). The Gear can be either a Driver or Driven Gear. For applications like expander or turbine which high-speed expander/turbine will drive the low speed bull gear and the low speed bull gear becomes the driven unit.

Influence coefficient method is used in the balancing calculation. The theory is based on two papers:

Tessarzik, J. M., Badgley, R. H., and Anderson, W. J., 1972, Flexible Rotor Balancing by the Exact Point-Speed Influence Coefficient Method, ASME Journal of Engineering for Industry, Feb., 1972, pp 148-158.

Lund, J. W. and Tonnesen, J., 1972, Analysis and Experiments on Multi-Plane Balancing of a Flexible Rotor, ASME Journal of Engineering for Industry, Feb., 1972, pp 233-242.

Since the least square method is used to solve the simultaneous equations, the Number of Measured Probes times the Number of Speed Points must be greater than or equal to the Number of Balancing Planes. (NsXNm >= Nb).

To use the influence coefficient method, no prior knowledge in rotor mode is required. However, trial weights are required to obtain the influence coefficients.

This thrust bearing program has been developed based on the finite element method to accurately predict the performance of various hydrodynamic thrust bearings, such as:

• Tilting pad thrust bearing with line or point pivot configuration
• Tapered land thrust bearing with single or compound tapers and uni- or bi-directions
• Rayleigh step thrust bearing with uni- or bi-directions.

Pad crown can be present and modeled for the tilting pad thrust bearing, particularly when the pivot is centrally located. The dam (shroud) can be present at inner and outer diameters for the taper land and step thrust bearings. Currently, only the sector-shape of the pad is allowed for the tilting pad thrust bearing. The tilting pad geometry is specified by the pad circumferential arc length (degree), and the pad inner and outer diameters. However, for the taper land and step bearings (fixed profile geometry bearings), commonly the constant oil groove width is specified instead of the pad arc. For the taper land and step bearings, this program allows for both options: 1. Specify the oil groove with a constant width, or 2. Specify the oil groove with a constant arc at the pitch diameter. Another unique feature is that this program allows for the partial arc bearing (sometimes called horseshoe type) where the bearing does not have a full 360 degrees extent.

Three different types of analysis options are included in this program to fully understand the bearing performance:

Constant viscosity, which only lubricant viscosity and density are required for the inputs. Density is used if turbulence effect is checked. Heat balance. In this option, the lubricant properties as a function of temperature are required for the simple heat balance calculation. However, constant viscosity is still used in the Reynolds equation, and the outlet (exit) temperature is calculated using the flow and power loss equation. Reynolds equation is solved along with the energy equation for the pressure and temperature distribution. This will give accurate temperature distribution and temperature reading at the probe location.

Another useful design feature provided in this program is the multiple runs, which allows the users to perform multiple design iterations to optimize the design. For multiple runs, only the changed parameters are entered in the table, blank and zero entries indicate the parameters are unchanged from the baseline design.

This advanced spiral groove face seal program was developed to accurately predict the performance of hydrodynamic spiral grooves and other groove shapes (oblique groove and radial groove) for face seals in gas applications such as air or other gases. The governing equation is the compressible Reynolds equation with rarefied gas dynamic effect, so that a high degree of accuracy can be obtained for low-pressure applications in the aerospace industry. Two types of slip flow correction methods are presented. Pressures are specified at both ID and OD of the seal. The groove depth can be a function of radial and circumferential coordinates, although a constant depth is commonly used. Both the inward and outward pumping geometries are included. The analysis option includes a single run analysis and multiple run. Multiple run allows for the design iteration and multiple cases comparison for optimization purposes. Various postprocessor graphics allows for easy presentation and result comparison.

Labyrinth seal analysis for turbomachinery rotordynamics analysis

This program was developed in the mid 1980’s for rotor dynamics design evaluation of machinery having toothed labyrinth seals. Options exist in the data entry to estimate the leakage flow entry swirl into the first tooth of the seal. The program compares well to CFD analysis of similar seals but the effects are slightly larger in DYNLAB (LabyDRBSF.exe), hence if the system is stable with DYNLAB coefficients, the machine will likely be stable concerning labyrinth seal effects.

The current version has a new pre- & post-processor with new features to assist in the analysis of several options of bladed labyrinth seals. The new front end (Labyseal.exe) was written by Dr. Wen Jeng Chen and includes a very helpful graphic display of the leak-path and indication of tooth placement.

Documentation: Labyseal Pre & post-processor for LabyDRBSF (PDF)

Thermal synchronous instability phenomena in rotor-bearing systems, also known as the Morton effect, can be generated by the temperature difference developing across the fluid film journal as a result of the viscous shearing within the lubricant of the bearing. Based on Morton Effect model, a user-friendly program has been developed for overhung rotors.

Documentation Complete paper and Dyrobes examples:

Design Tool for Predicting Thermal Synchronous Instability by R. Gordon Kirk (PDF)

Release notes for Morton Effect optional program: Dyrobes Improvements for Ver 20.10 (PDF)