Services

Cooperation With DynLab

Are you interested in getting access to expert knowledge and modern research facilities for advanced research and innovation in the field of designing rotating systems and subsystems? Are you solving a problem you can’t handle, or you lack the necessary equipment? Or do you want to learn more about advanced methods of rotor systems design, their dynamics, and vibrodiagnostics?

 

We offer you to cooperate on scientific research projects with DynLab. We will deliver a complex solution for industrial orders with the possibility of connecting experimental and computational modelling in the field of rotor system dynamics.

 

We offer to create special computer software. We do not try to compete with universal commercial programs that address a specific problem only marginally. By creating a single-purpose program, we will achieve easier setting of input data, faster calculations, and more efficient reading of results.

 

DynLab also provides consultations, training, and lecturing in the mentioned areas.

Dynamics of Rotors and Bearings

We address measurement and computational modelling of special bearings of various types and dimensions according to specified parameters such as rotational speed, load, clearance and others. Calculations and measurements apply to hydrodynamic and aerodynamic bearings. We commonly consider these lubricants:

  • Liquid lubricants of normal viscosity (oils of type ISO VG 2-32 and others)
  • Low-viscosity lubricants (water, highly concentrated chemicals such as peroxide and others)
  • Gases (air, helium and others)
 

We perform measurements and calculations of the following types of bearings for the mentioned types of lubricants:

  • Tilting-pad bearings (hydrodynamic, aerodynamic)
  • Multiple-pad bearings
  • Lemon-bore (elliptical) bearings
  • Offset bearings
  • Cylindrical hydrodynamic bearings (plain)
 

Experimental Modelling

Measurement of static performance of bearings

  • Measurement of the static equilibrium position of the journal (depending on rotational speed, load and other parameters)
  • Measurement of the shaft vibrations (RMS amplitude, peak-to-peak amplitude)
  • Visual inspection of wear of the sliding surfaces (using a microscopic lens)
  • Lubricant temperature measurement
  • Power dissipation measurement
 

Measurement of dynamic performance of bearings

  • Measurement of stiffness coefficients (depending on rotational speed, load and other parameters)
  • Measurement of damping coefficients (depending on rotational speed, load and other parameters)

Computational Modelling

Computational modelling of static performance of journal bearings lubricated by liquids and gases

  • Calculation of pressure distribution in the bearing
  • Calculation of the temperature field in the bearing
  • Calculation of the viscosity and density distribution at the lubricant film depending on the current temperature and pressure
  • Calculation of the lubricating film distribution
  • Calculation of the equilibrium position of the bearing (equilibrium position of the journal as well as equilibrium tilt of the pads depending on speed, load and other parameters)
  • Power dissipation calculation
 

Computational modelling of dynamic performance of journal bearings lubricated by liquids and gases

 

  • Calculation of stiffness coefficients depending on rotational speed, load and other parameters
  • Calculation of damping coefficients depending on rotational speed, load and other parameters
  • Calculation of the complete stiffness and damping matrix
  • Calculation of stability of individual pads
 
Design and computational verification of the correct design of hydrodynamic and aerodynamic journal bearings
  • Design of dimensions and type of bearing
  • Calculation of the minimum thickness of the lubricant film
  • Calculation of static and dynamic performance of the bearing
  • Experimental verification
 

Design, analysis and optimization of rotors and their supports

  • Strength analyses of rotary systems
  • Calculations of natural rotor vibration shapes and frequencies including speed-dependent dynamic characteristics of the supports
  • Calculation of critical speeds, their representation in the Campbell diagram
  • Calculation of bearing effect on critical speed position and rotor stability
  • Calculation of forced vibration (e.g., imbalance)
  • Modal, harmonic or transient analyses 
 
Calculation of rotor dynamics
 
Design of bearing testing 
  • Design of experiments (static, dynamic, and vibration tests)
  • Performing of experiments
  • Design of test devices according to individual requirements
 

Structural Dynamics and Vibrodiagnostics

Experimental Modelling

  • Classical experimental modal analysis (determination of natural frequencies, shapes and damping during excitation by a modal hammer or modal shaker)
  • Measurement of operating oscillation shapes (determination of oscillation shapes during machine operation)
  • Operational modal analysis (determination of natural frequencies, shapes and damping during machine operation)
  • Vibrodiagnostics (vibration measurement and fault diagnostics, longer-term measurement)
  • Measurement of vibrations and frequency characteristics (general measurement according to the customer requirements)

Computational modelling
  • Strength analyses with static loads
  • Modal analysis for determining natural frequencies and natural shapes
  • Harmonic analyses to determine the frequency-dependent harmonic excitation response
  • Transient analyses to determine the response to the time-dependent excitation, e.g., rotor start with imbalance