Engine acoustics and mechanics are very closely related fields, since the physical design of the components and the tribological boundary conditions during operation affect the acoustic behavior of the engine. In addition, there are interactions between combustion and the mechanics due to the
- dynamic characteristic of the gas forces – also and especially in the higher-frequency range (combustion noise)
- mechanical loading and inertia forces of the moving engine components.
- coupling of these components via nonlinear hydrodynamic films of lubricant
As part of a holistic optimization of the noise behavior, these dependencies must be taken into consideration; right through to the effect on consumption and exhaust emissions/after treatment.
Piston pin suspension:
- Measurement of piston pin movement in 2 radial directions with noncontact travel sensors
- Measurement of axial pin movement and rotation against helical surface
- Link for guiding the measuring signal lines
- Determination (strip investigations) and reduction of friction of individual engine components
- High-precision torque measurement and regulation of oil and coolant temperature
- Temperature and pressure-controlled external oil supply
- Determination of mean pressure with indication
- Max. speed/torque 10,000 rpm/725 Nm
Computer-Aided Design (CAD)
- Design and optimization of engine components
- Development of test bench components
- Creation of 3D models for numerical calculations
Finite Element Method (FEM)
- Investigation of vibration behavior of engine components
- Holistic simulation of mechanical engine systems (crankgear/valve gear)
Combustion noise optimization based on engine-specific structure transfer dimension under consideration of target conflicts concerning consumption and exhaust-gas emission
Subdividing engine noise into:
- Direct combustion noise
- Indirect combustion noise
- Mechanical Noise
Mechanical noises are created by the dynamic forces of the rotating and oscillating components and by the movement of components within their running clearance, e.g. piston – cylinder and bearing journal – bearing shell. In the crankgear, gas and inertia forces overlap and lead to the excitation of indirect combustion noises.
The measurement of these movements together with their resulting structure-borne sound excitation is carried out using noncontact travel sensors on an eddy-current basis.