Laboratory for piston machines

Teaching

Piston machines include the areas of combustion engines, compressors and pumps.

In addition to the lecture on Piston Machines I, the corresponding practical exercises take place in the laboratory. Using application-oriented examples, in this case pump and compressor test bench, the students learn to consolidate the knowledge acquired in the lecture and to assess the function of the machines in real tests.

The compulsory elective module Piston Machines II also includes the practical laboratory exercise, here the performance data of a petrol and diesel engine are determined on the engine test bench. This includes, among other things, the fuel consumption, the performance and the exhaust gas values of the unit to be tested. The prerequisite for this is a good transfer knowledge of the students in the area of thermodynamics and measurement technology. The knowledge from the lectures Piston Machines II and the thermodynamics lectures can be applied practically in this case as well. The experiment is carried out by the students on their own after thorough instructions. This promotes teamwork and independence.

Project work - from friction and wear examinations to the beer crate runner - is always carried out. The Bachelor's and Master's theses are mainly offered in cooperation with industrial companies. 

Research

Many R&D projects have arisen around the topic of friction, wear and oil consumption. Here are three examples:

  • The lubricating film that forms under the piston rings plays a decisive role in ensuring that the tribological system of piston ring - cylinder functions properly and has low wear. The oil consumption that inevitably occurs as a result should be as low as possible. To better understand this system, it is helpful to visualise the oil film under the piston rings and the piston skirt.
  • Oil consumption also plays an important role in the air compressors. In the laboratory, there is a test bench with the help of which the compressors are examined for their oil consumption. Established and newly developed measuring methods are used for this purpose.
  • Materials from the valve train are exposed to the highest mechanical and thermal loads in modern combustion engines. In addition, they should have good thermal conductivity, be light and generate low material costs. Many of these materials are manufactured using the sintering process and can be extensively tested either as a material test using an SRV tribometer or in the existing component test benches. 

 

Equipment

Test benches:

  • Three motor test benches (up to 160 kW, 10000 RPM (1/min)).
  • SRV and rotation tribometer
  • Compressor test bench
  • Principle test rigs for the wear examination of valve train components
  • Test engines for determining octane and cetane numbers
  • Engines with glass cylinders for oil film examination and charge movement
  • Injection pump test bench
  • Drag test bench +/- 10 kW
  • Steam engine

Analytics:

  • High-speed camera (up to 10000 fps)
  • Digital microscope Keyence VHX-6000 (up to 1000x magnification)
  • Exhaust gas tester AVL
  • Blow By Meter AVL
  • Stereo microscope
  • Oscilloscope
  • Transient recorder (Dewetron)
  • Piezo pressure transducer and pressure measuring spark plug with the corresponding charge amplifiers
  • Ahlborn measurement technology for various applications (e.g. temperature, voltage and pressure)

Tools:

  • Engine-specific special tools
  • Extensive means for measuring engine components
  • OBD for vehicles from the VW group  

Impressions

The team