Establishing a Target for Control of Diesel Combustion Noise

The minimum practicable levels of diesel combustion noise and mechanical noise, which might be achieved by control at source, are estimated for direct injection engines of 1 litre per cylinder capacity, as used in trucks and tractors of European manufacture. These levels are compared with targets derived from proposals for more stringent noise legislation for such vehicles. The targets might be achieved by a combination of control of combustion and mechanical noise at source and reduction of the engine structure response to these sources.