Fuel agnostic compression ignition engine

The method of any of the preceding claims, wherein the fuel is a first fuel, the volume of intake charge is a first volume of intake charge, and the timing of fuel injection is a first timing with respect to the events of the engine cycle, the method further comprising:

• receiving a volume of intake charge in the combustion chamber;
• compressing the intake charge;
• injecting a volume of a second fuel into the combustion chamber at a second timing with respect to the events of the engine cycle, during a second time period, the second fuel having a different cetane number, heating value, and/or chemical composition from the first fuel;
• combusting substantially all of the volume of the second fuel,
• wherein the second engine crank angle is sufficiently late in the compression process such that no more than about 50% of the volume of the second fuel is pre-mixed with the second volume of intake charge upon initiation of combustion.

A method of operating a compression ignition engine, the compression ignition engine including a combustion chamber, the method comprising the steps of:

• receiving a volume of intake charge in the combustion chamber;
• compressing the volume of intake charge to arrive at an effective compression ratio of at least about 15:1;
• injecting a volume of fuel into the combustion chamber, the fuel having a cetane number less than about 40;
• and
• combusting substantially all of the volume of fuel,
• wherein the injection timing is sufficiently late in the compression process such that at least 30% of the energy generated from combusting the volume of fuel is generated while the volume of fuel is being injected into the combustion chamber,
• and wherein the compression ignition engine includes at least one of a two-stroke engine, an opposed-piston engine, a two-stroke opposed piston engine, a five-stroke engine, a six-stroke engine, a free-piston engine, a free piston engine linear, a rotary engine, or a Wankel rotary engine.

A method of operating a compression ignition engine, the compression ignition engine including a combustion chamber, the method comprising the steps of:

• receiving a volume of intake charge in the combustion chamber;
• compressing the volume of intake charge in the engine to arrive at an effective compression ratio of at least about 15:1, and a pressure and temperature sufficient to induce autoignition in the combustion chamber,
• injecting a volume of fuel into the combustion chamber at a first timing, the volume of fuel having a cetane number less than about 30;
• and
• changing the injection timing of the volume of fuel to control the rate of pressure rise from the combustion of the volume of fuel in the volume of intake charge to be less than about 15 MPa/ms,
• wherein the compression ignition engine includes at least one of a two-stroke engine, an opposed-piston engine, a two-stroke opposed piston engine, a five-stroke engine, a six-stroke engine, a free-piston engine, a free piston engine linear, a rotary engine, or a Wankel rotary engine.

A method of operating a compression ignition engine, the compression ignition engine including a combustion chamber, the method comprising the steps of:

• receiving a first volume of intake charge in the combustion chamber;
• compressing the volume of intake charge in order to arrive at an effective compression ratio of the volume of intake charge of at least about 15;
• injecting a volume of a first fuel into the combustion chamber at a first injection timing during a first time period into the volume of intake charge having a first temperature, the first temperature measured at 1 ms prior to injecting the volume of the first fuel into the combustion chamber, the first fuel having a first cetane number less than about 40;
• combusting substantially all of the volume of the first fuel;
• receiving a second volume of intake charge in the combustion chamber;
• compressing the second volume of intake charge and arrive at an effective compression ratio of at least about 15;
• injecting a volume of a second fuel into the combustion chamber during a second time period into the second volume of intake charge, the second volume of intake charge having a second temperature higher than the first temperature, the second temperature measured at 1 ms prior to injecting the volume of the second fuel into the combustion chamber, the second fuel different than the first fuel and having a second cetane number lower than the first cetane number;
• combusting substantially all of the volume of the second fuel, wherein
• a delay between injecting the volume of the first fuel and the second fuel into the combustion chamber and initiation of combustion of each fuel is less than about 2 ms,
• and wherein the compression ignition engine includes at least one of a two-stroke engine, an opposed-piston engine, a two-stroke opposed piston engine, a five-stroke engine, a six-stroke engine, a free-piston engine, a free piston engine linear, a rotary engine, or a Wankel rotary engine.