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XLRotor is fast, and because XLRotor models are transportable to our clients and suppliers, we can easily share results and make difficult decisions in a minimum amount of time. I should also note that the capability and functionality of XLRotor continues to expand. As far as support, Dr. Murphy responds almost immediately to any questions or issues we may have

Robert C. Eisenmann
Senior Engineering Advisor, Sulzer Turbo Services Houston Inc.


XLHydroDyn is an optional module for design and analysis of hydrodynamic fluid film (radial) bearings. The analysis is a full-film solution of Reynolds equation. The program offers many options enabling it to handle a wide variety of applications. The full version of XLHydroDyn is included in the downloaded demo version of Xlrotor.

  • Fixed geometry bearings, tilting pad bearings, deflection pad bearings, pressure dam bearings, taper land, and many more
  • Arbitrary journal loading (for gear loads, etc.)
  • 1D and 2D solution options
  • Isothermal, adiabatic or full heat conduction options
  • Full direct analysis, not pad assembly
  • Includes thermal and structural pad deformations
  • Includes pivot deformations
  • Allows preload and axial length unique to each pad
  • Journal position can be calculated for a given load, or specified directly
  • Calculates power loss, temperature rise and pad flows
  • Calculates full 2D pressure and temperature distributions
  • Variable cross-film temperature and viscosity
  • Laminar and turbulent flow
  • Fast, robust nonlinear solver
  • Oils are selectable from extensive library, or user defined
  • Work in either US or SI units

Included with every XLRotor license is a fluid film bearing module called XLJrnl, which is a table-lookup program. It covers standard bearing types in typical applications. In general XLJrnl can provide reasonable estimates for linear force coefficients, but is not suitable for designing bearings from scratch. XLJrnl requires the input of lubricant viscosity in the bearing oil film, and results can be highly dependent on this particularly at conditions of high speed and/or load. Whereas XLHydrodyn does a full thermal solution to determine oil film temperature from inlet conditions. Another important difference is that in XLJrnl the applied load must be downward, and in XLHydrodyn it can be any direction (e.g. gear reaction loads).