Quasi-static assessment of the root stresses of 3D gear models. Different load magnitudes and distributions were investigated. Mesh convergence study performed. Analysis software: ANSYS.
Calculation of the eigenfrequencies of a five stage vertically suspended pump who was indicating high vibration levels on site. Mode comparison with field measurements. Assessment of the vibration amplitudes with harmonic response analysis. Design and implementation of mitigation measures.
Investigation of the rotordynamic stability of multistage pumps of different configurations (number impellers, diffuser, blind stages). Influence of various fluid types (Light—>Medium—>Dense) and design concepts analysed (swirl breaks, serrations, etc.). More than 50 FEA calculations performed (damped modal analysis, damped harmonic response analysis). Rotor geometry: 1D (beam) elements: 300 nodes, Non-linear rotordynamic effects included: Bearings, Annular seals, etc., Analysis software: MADYN.
Calculation of the modes of a horizontal pump-motor-baseplate assembly which was showing unacceptable vibration behavior on field using FEA. Investigation of various modeling approaches to match field test results (influence of water mass, boundary conditions, mounting options of pump-baseplate [fixed contact, bolt modelling]) Design and evaluation of mitigation measures [geometry improvements (various beams, plates, ribs, seams]). Analysis software: SimCenter (SOL103).
Analysis of the dynamic characteristics of a fully assembled pumping system (motor-baseplate-pump). Introduction and assessment of design modifications to minimize vibrations. Parallel assessment of the accuracy of different simulation modelling techniques: MPCs/bonded connections, motor modelling, etc. Main simulation characteristics: 2D shell, 3D solid (hexahedral + tetrahedral) elements. Software: Siemens Simcenter (SOL103), 2M nodes.
Caclulation of the lateral rotordynamic behavior of a twelve stage multiphase pump. Calculation was performed in air and water according to API610, and design modifications were investigated to improve the rotordynamic performance. Integrated squeeze film damper potential was investigated as well.
Calculation of the eigenfrequencies of bearing housings and optimisation of the bearing housing geometry to avoid excessive vibration. Advanced simulation techniques (prestressed analysis) implemented. Software: ANSYS, 500k nodes.
The project was about axially split pumps for which O-Rings were used instead of flat gaskets to seal the two casings. O-Rings can seal higher pressures so larger casing deformations might be accepted. In this project different rib configurations on the top casing were calculated to provide maximum stiffness at minimum weight. Critical mechanical integrity failure modes (tightness, plastification, etc.) were assessed, too.
Thermal (steady state) and structural simulation (weak coupling) of hot centrifugal pumps. Design assessment in terms of deformations and stresses.
Investigated failure modes: Plastic collapse, Brittle failure (linearization procedures), Loss of tightness (contact gap criteria), Fastener failure (semi-analytical based on forces/moments: extracted from FEM). FEM Model: 3D hexahedral & tetrahedral elements, approx. 1.5M nodes. Special finite elements programmed to model thread connections (1D non-linear spring elements). Different physical forces modeled (pretension + hydraulic forces + thermal loads + fluid pressure). Boundary conditions: deformable Multi-Point-Constraints. Simulation software: ANSYS, NASTRAN (SOL 101/103/401).
End-of-life assessment of an impeller operating in partial load conditions. CFD was done for two impeller rotations (720 pressure fields). The pressure fields were imported in ANSYS WB and were rotated to match the (non-rotating) impeller. Quasi static calculations were performed to determine the corresponding 720 stress states (equivalent stresses). FKM plug-in of ANSYS was used to perform the assessment of the fatigue life of the machine (utilisation factors).
Development of a computation module for calculating the root stress of gears using a three or two dimensional model. Programming language: C++, Frontend: Qt, IDE: Visual Studio 2017. Appropriate unit testing, validation (ANSYS) and documentation created as well.
Development of a computational module for calculating the stiffness of gear bodies. Incorporation of the module to other computatiional modules (e.g. contact analyis of gears). Programming language: C++, Frontend: Qt, IDE: Visual Studio 2017. Appropriate unit testing, validation and documentation created as well.
Development of a GUI which incorporates rotordynamic codes programmed in FORTRAN 77. The codes were able to compute the stiffness, damping and mass matrices of annular seals in laminar/transition/turbulent regimes. Programming language: C#, Frontend: FPSpread (GrapeCity). Appropriate unit testing, validation and documentation created as well.
Full stack development of a Siemens Simcenter plug-in to perform stress evaluation of various fastener connections. Main features: seperate material database, calculation of 10 different stress types, support of different fastener geometries. Programming language: C#, Frontend: Windows Forms, IDE: Visual Studio 2019. Appropriate unit testing, validation and documentation created as well.
Full stack development of a program able to calculate stresses and deformations on flange connections. Programming language: C#, Frontend: FPSpread (GrapeCity), API: NX Open, IDE: Visual Studio 2017, calculation core: NASTRAN. Unit testing implemented and appropriate documentation created as well.