Targeted Airflow - FloEFD Used for Flow Simulation at Océ
The Dutch printer manufacturer Océ has its headquarters for production printing systems in Poing before the gates of Munich. Research and development, production, quality assurance, training, sales and service are grouped together at this site. Printing systems for internal and external use are developed and manufactured here.
“However, we have now progressed so far that we only carry out 10% of the tests which were previously necessary. The simulation has thus also led to an enormous cost saving in terms of test set ups”
Océ is committed to research and development
And Océ places great emphasis on research because it develops its own technologies. This commitment to research and development guarantees professional document solutions in digital, colour and software applications and applications with web capabilities. The flow ratios within the printer need to be constantly optimised in order to secure and increase the quality of the printout. And to this end Dipl.Ing (T.U.) (Graduate engineer at a University of Applied Science) Rainer Hoffmann, director of Development, Technology and Key Components, has been using NIKA’s FloEFD flow simulation software as an aid since the end of 2003. Hoffmann works in the areas of modelling and simulation in general: “I am the theorist in the company and more involved in research than in development. I do not just simulate air flows but also other sub-processes in the printing process such as finite elements, electrostatics or magnetostatics, and also the toner movement within the printer. This air flow is just one section of my work.”
High demands on FloEFD
Rainer Hoffmann did not make his decision in favour of FloEFD easily. He tested different systems with similar functions, which were all, however, unable to meet his requirements. “The simulation software is so powerful that you are also dependent on obtaining suitable support from the manufacturer” according to Hoffmann. “In this case capable people must be on the phone who can solve the pending problems within a short space of time. This was the case at NIKA.”
Hoffmann did not undergo any training. He was able to learn the skills himself using tutorials and manuals because he had already intensively concerned himself with simulation programs prior to this. However, six designers were trained, who were already able to see how the component should be constructively adapted to engineering flow requirements during design. Up to now people had only been able to rely upon the experience of the developers. However, Hoffmann “the researcher” exploits the simulation software to its very limits. He calculates the ventilation and the suction of the charging units within the printer. The photoconductor of the printer must be loaded with high-voltage wires, which have to be constantly ventilated to function properly. The calculation problem results from the geometry of the long and thin wires. Their even ventilation must work throughout the entire length. If deviations are present then this becomes visible in the form of an annoying stripe, which will certainly not delight the customers.
Convincing performances of the software
The decisive thing for the development manager was that the software masters this geometry even if it meets up with its limitations in the process. “We could indeed do with more performance, but FloEFD was the only program capable of rendering this level of performance,” as Rainer Hoffmann confessed. “Four points convinced me:
- The data can be seamlessly imported from our Pro-Engineer construction software. This is a definite plus.
- Even difficult geometries can be implemented relatively well. You can now work efficiently with the meshing in the new version.
- The most important point is that the calculation always converges. Nevertheless the calculation times are always very long – 24 hour cycles are normal.
- It is also possible to make the process clear to people who do not understand much about the subject matter by means of the attractive visualisation. It is also easier to sell the work in this way.
However, the software alone does not lead to better development results; the results of the simulation must also be interpreted correctly. Therefore a lot of experience is necessary in order to make the right decisions. “We still imitate certain geometries in tests so that we can control the final result,” as Hoffmann explains. “However, we have now progressed so far that we only carry out 10% of the tests which were previously necessary. The simulation has thus also led to an enormous cost saving in terms of test set ups.” The flow simulation successes with FloEFD at the Océ company will also certainly ensure that further processes are investigated and that constructive optimisations to the products are certain.