We can currently offer the following topics for dissertations:

Calculation of necessary housing wall thicknesses

Internal system pressures and flow strengths put a strain on ventilators. Whereas the strain from system pressures is easy to estimate, the influences of the flow and the drive on the oscillation behaviour of the ventilator housing are complex.
With the help of simple contexts, the aim is to faciliate statements about the necessary wall strengths of the housings. The option of using stiffening should be taken into account here.

The following work steps are planned:
•    Compilation of all influences incl. weighting
•    Calculation of the wall strengths without stiffening (pressure influence; deformations according to work sheets pressure containers and plate theory) 
•    Influence of stiffening (e.g. according to TRB 305)
•    Assessment of the quantitative influence of oscillations (key words: natural frequency, notional pressure)
•    Load of spiral, suction supports and pressure supports – required dimensions

Excel and CAD programmes should be used as tools. The documentation of the results will be done with Word.


Creation of danger and risk analyses for ventilators

Pursuant to the machine directive, manufacturers of machines are obliged to create risk analyses for their products. General and specific instructions, on risks and their prevention can be found in various norms. As examples, the requirement for the covering of a belt drive or reliable material couplings for the avoidance of spark formation with ventilators for the explosion-proof area are given.

An instrument is to be created for FIMA ventilators that enables danger and risk analyses to be created quickly and comprehensively. The different design forms and areas of application of the ventilators are to be taken into account here.

The following work steps are planned:
•    Literature research – relevant norms are to be analysed with regard to danger analysis and risk analysis
•    Depiction of required measures for reducing/avoiding risks
•    Comparison of software tools for the creation of risk analyses
•    Determination of risk potentials of some selected ventilator design series
•    Development of a tool for danger analysis that is adapted to FIMA
•    Documentation of the results.


Programme for the calculation of reaction strengths to the oscillation of ventilators

In most cases, ventilators are installed in conduits. Compensators are used for oscillation insulation. Internal pressure, conduit strengths and heat expansions lead to forces that affect pressure and suction supports of the ventilator. These forces are discharged into the base via vibration dampers.
With the help of a programme, the possibility of calculating the forces and deflections at the bearing points is to be created.

The following boundary conditions are to be taken into account:
•    External forces
•    Weights
•    Internal pressure
•    Heat expansion (material)
•    Compensator stiffness
•    Damper stiffness

The following results are expected:
•    Powers and shifts at the support points
•    Powers and torques at the supports

Excel and programming languages that are yet to be defined should be used as tools. The documentation of the results will be done with Word.

Interested students should contact:
Dr Axel Müller
Tel +49 (0) 7973 693 277
e-mail: a.mueller(a)fima-sha.de