Analysis and Reduction of Piston Slap Noise in Diesel Engines

Piston slap is one of the major sources of noise in a 4-cycle diesel engine. Reduction of it is essential in reducing total engine noise.

For the purpose of reducing piston slap noise, piston lateral transverse movement was simulated using a new analytical model which considers not only the effect of oil cushioning, but also piston deformation, within a reasonable computing time.

The simulation results showed that the modification of piston profile, as well as piston pin center offset and reduction of piston-liner clearance, can reduce the piston slap force. As a result, an improved piston profile was designed for reducing slap noise, and the effect of the improved piston on noise reduction was proven.