enginesdiesel

Diesel engines are internal combustion engines that operate on the diesel cycle. They rely on compression ignition rather than spark ignition: air is compressed to very high temperatures and pressures, and fuel is injected into the hot air, igniting spontaneously. Diesel engines are noted for high thermal efficiency, robust torque, and long durability, which has led to their widespread use in heavy trucks, buses, ships, industrial equipment, and power generators.

In typical designs, intake air is compressed in the cylinder to a high pressure, raising its temperature, and fuel is injected under high pressure through a pump or common-rail system. The timing, pressure, and number of injections affect efficiency and emissions. Most modern diesels employ turbocharging and intercooling to increase air density, with multi-cylinder arrangements chosen for balance, power, and noise reduction.

Diesel engines range from small automotive units to large marine and stationary installations. They power heavy-duty trucks, buses, construction equipment, locomotives, and ship propulsion, while stationary diesel engines drive generators for backup power, remote sites, and industrial processes.

The diesel engine was conceived by Rudolf Diesel in the 1890s, with the first working engine demonstrated in 1897. Early models used relatively heavy fuels and suffered cold-start issues; subsequent developments increased compression ratios, refined fuel-injection systems, and enabled wide commercial use across industries.

Diesel engines typically achieve higher thermal efficiency than gasoline engines, especially at steady or high-load operation. Modern designs include advanced fuel injection systems, turbocharging, intercooling, and exhaust-aftertreatment such as diesel particulate filters (DPF) and selective catalytic reduction (SCR) to reduce particulates and nitrogen oxides. Regulatory standards (for example Euro 6/Stage V) continue to push reductions in emissions and fuel consumption.