‘MCR – Radial Piston Motor’
3D Pressure Map’
‘Dynamic Full System Simulation’
Bosch Rexroth – www.boschrexroth.co.uk
Bosch Rexroth collaborate with Leicester University to validate the CFD simulation of a Radial Piston Motor
Economical, precise, safe and energy efficient: Drive and Control technology from Bosch Rexroth moves machines and systems of any size. The company bundles global application experience in the market segments of Mobile Applications, Machinery Applications and Engineering, Factory Automation, and Renewable Energies to develop innovative components as well as tailored system solutions and services. Bosch Rexroth offers its customers hydraulics, electric drives and controls, pneumatics, gear technology, and linear motion and assembly technology all from one source.
A major part of Bosch Rexroth’s Engineering Strategy in Scotland, is to increase the understanding of the MCR radial-piston motor’s function and operation through accurate modelling and simulation. This will allow the range of MCR motors to be optimised in terms of flow losses and pressure fluctuations. Computational fluid dynamics (CFD) software has been demonstrated to the company in recent years and one software package in particular; PumpLinx provided in the UK by 80/20 Engineering, appeared to provide the ability to model dynamic fluid-power components relatively easily.
As part of a final year thesis project at Leicester University an MCR radial-piston motor was modelled using the CFD software Pumplinx. The results of the CFD simulations were compared to experimental results provided by Bosch Rexroth and the correlation between these results was then further optimised using certain best practices and methods. Due to this being a new engineering development for Bosch Rexroth, there was little internal knowledge to follow, therefore a procedure was developed and defined for use throughout the project and on any future work with support from 80/20 Engineering.
This procedure allowed for improved time efficiency and was passed onto Bosch Rexroth to assist with the implementation of Pumplinx as a useful development tool.
The MCR motor was selected by Bosch Rexroth as there was experimental data from extensive testing carried out at the Research & Development (R&D) centre located in Glenrothes, Fife. The data included pressure readings in the piston bore as well as the standard pressure readings at the inlet and outlet ports. This was desirable as it would allow for more accurate comparisons to de drawn between the test data and the PumpLinx simulation results i.e. more points to compare.
At the start of the project the main objectives were to find out if Pumplinx could accurately model a radial-piston motor during operation and then to refine the model to attain the best possible correlation between the simulation and R&D test results. These objectives were completed and the PumpLinx software has been proven to be able to accurately model the MCR motor during the full operational cycle. Further improvements of the model resulted in an improved correlation of the results and due to this success a general procedure was outlined to be used as a framework and benchmark for further development work. The PumpLinx software is now being used as a reliable design tool for Bosch Rexroth’s MCR radial-piston motor’s development and is helping to improve design to achieve higher mechanical efficiencies and lower noise outputs.
A Paper entitled ‘Computational Fluid Dynamics Modeling of a Hydraulic Radial Piston Motor’ was presented at the International Conference on Mechanics, Building Material and Civil Engineering (MBMCE 2015), Guilin, China with joint authors from Bosch Rexroth and Leicester University.