Dynamic Behaviour of a Turbocharged Diesel Engine

The transient behaviour of torque and smoke produced by a turbocharged diesel engine has been measured by frequency response methods, with a sinusoidal perturbation applied to the fuel. A dynamic torque parameter (dmep) has been introduced and the response of this to changes in speed and load can be separated. The dmep also enables the delay associated with torque production to be obtained: this is compared to the widely accepted values.

The results have also been analysed to show the relationship between air-fuel ratio and smoke produced during a transient. The conclusion is that the production of smoke under dynamic condition, behaves similarly to that under steady running but that it is more dependent on the initial load (air-fuel ratio) level.