Abstract: Low-reactivity fuel such as gasoline is provided to a diesel engine cylinder sufficiently early in the injection stroke that it will be premixed. High reactivity fuel such as diesel fuel is then injected during the compression stroke, preferably around 40-60° before Top Dead Center (TDC), to provide a stratified distribution of fuel reactivity within the cylinder, one which provides ignition (the start of main heat release) at or near TDC, preferably at 0-10° prior to TDC. At that time, the low-reactivity fuel is again injected and burns in a diffusion-controlled manner owing to its lower reactivity, thereby providing greater power output (and thus increased load) with little or no increase in peak heat release rate (PHRR) and combustion noise.

Abstract: A compression ignition (diesel) engine uses two or more fuel charges during a combustion cycle, with the fuel charges having two or more reactivities (e.g., different cetane numbers), in order to control the timing and duration of combustion. By appropriately choosing the reactivities of the charges, their relative amounts, and their timing, combustion can be tailored to achieve optimal power output (and thus fuel efficiency), at controlled temperatures (and thus controlled NOx), and with controlled equivalence ratios (and thus controlled soot). At low load and no load (idling) conditions, the aforementioned results are attained by restricting airflow to the combustion chamber during the intake stroke (as by throttling the incoming air at or prior to the combustion chamber's intake port) so that the cylinder air pressure is below ambient pressure at the start of the compression stroke.

Abstract: Low-reactivity fuel such as gasoline is provided to a diesel engine cylinder sufficiently early in the injection stroke that it will be premixed. High reactivity fuel such as diesel fuel is then injected during the compression stroke, preferably around 40-60° before Top Dead Center (TDC), to provide a stratified distribution of fuel reactivity within the cylinder, one which provides ignition (the start of main heat release) at or near TDC, preferably at 0-10° prior to TDC. At that time, the low-reactivity fuel is again injected and burns in a diffusion-controlled manner owing to its lower reactivity, thereby providing greater power output (and thus increased load) with little or no increase in peak heat release rate (PHRR) and combustion noise.

Abstract: A compression ignition engine uses two or more fuel charges having two or more reactivities to control the timing and duration of combustion. In a preferred implementation, a lower-reactivity fuel charge is injected or otherwise introduced into the combustion chamber, preferably sufficiently early that it becomes at least substantially homogeneously dispersed within the chamber before a subsequent injection is made. One or more subsequent injections of higher-reactivity fuel charges are then made, and these preferably distribute the higher-reactivity matter within the lower-reactivity chamber space such that combustion begins in the higher-reactivity regions, and with the lower-reactivity regions following thereafter.

Abstract: A compression ignition engine includes a piston having a barrier protruding axially therefrom. The barrier at least partly defines a combustion chamber having a first zone separated from a second zone by the barrier. An initial fuel charge is supplied into the combustion chamber, and a subsequent fuel charge is supplied into the first zone, the subsequent fuel charge having greater reactivity than the initial fuel charge. The fuel charges are compressed to induce ignition and combustion of the fuel charges, such that the subsequent fuel charge burns within the first zone to produce hot gases, and the hot gases flow across the barrier to effect combustion of the initial fuel charge within the second zone.

Abstract: A compression ignition engine uses two or more fuel charges having two or more reactivities to control the timing and duration of combustion. In a preferred implementation, a lower-reactivity fuel charge is injected or otherwise introduced into the combustion chamber, preferably sufficiently early that it becomes at least substantially homogeneously dispersed within the chamber before a subsequent injection is made. One or more subsequent injections of higher-reactivity fuel charges are then made, and these preferably distribute the higher-reactivity matter within the lower-reactivity chamber space such that combustion begins in the higher-reactivity regions, and with the lower-reactivity regions following thereafter.

Abstract: A compression ignition engine uses two or more fuel charges having two or more reactivities to control the timing and duration of combustion. In a preferred implementation, a lower-reactivity fuel charge is injected or otherwise introduced into the combustion chamber, preferably sufficiently early that it becomes at least substantially homogeneously dispersed within the chamber before a subsequent injection is made. One or more subsequent injections of higher-reactivity fuel charges are then made, and these preferably distribute the higher-reactivity matter within the lower-reactivity chamber space such that combustion begins in the higher-reactivity regions, and with the lower-reactivity regions following thereafter.

Abstract: A first fuel charge having low reactivity (low cetane number) is injected into a rotary engine, such as a Wankel engine, sufficiently early during the intake stroke that a subsequent higher-reactivity injected fuel charge forms one or more stratified high-reactivity regions within the engine chamber. Compression ignition then begins at the high-reactivity regions and propagates to the lower-reactivity regions. Appropriate choice of the timings, quantities, and other parameters of the injections can allow control of the timing and rate of combustion, such that work output can be maximized, unburned fuel can be minimized, and chamber temperature can be controlled to reduce heat losses and NOx emissions. As a result, rotary engine efficiency can be enhanced while emissions are reduced. Since the invention can be implemented in a lightweight and compact rotary engine, it is well suited for use in hybrid and compact vehicles.

Abstract: A compression ignition (diesel) engine uses two or more fuel charges during a combustion cycle, with the fuel charges having two or more reactivities (e.g., different cetane numbers), in order to control the timing and duration of combustion. By appropriately choosing the reactivities of the charges, their relative amounts, and their timing, combustion can be tailored to achieve optimal power output (and thus fuel efficiency), at controlled temperatures (and thus controlled NOx), and with controlled equivalence ratios (and thus controlled soot). At low load and no load (idling) conditions, the aforementioned results are attained by restricting airflow to the combustion chamber during the intake stroke (as by throttling the incoming air at or prior to the combustion chamber's intake port) so that the cylinder air pressure is below ambient pressure at the start of the compression stroke.

Abstract: A compression ignition (diesel) engine uses two or more fuel charges during a combustion cycle, with the fuel charges having two or more reactivities (e.g., different cetane numbers), in order to control the timing and duration of combustion. By appropriately choosing the reactivities of the charges, their relative amounts, and their timing, combustion can be tailored to achieve optimal power output (and thus fuel efficiency), at controlled temperatures (and thus controlled NOx), and with controlled equivalence ratios (and thus controlled soot). At low load and no load (idling) conditions, the aforementioned results are attained by restricting airflow to the combustion chamber during the intake stroke (as by throttling the incoming air at or prior to the combustion chamber's intake port) so that the cylinder air pressure is below ambient pressure at the start of the compression stroke.

Abstract: A compression ignition engine uses two or more fuel charges having two or more reactivities to control the timing and duration of combustion. In a preferred implementation, a lower-reactivity fuel charge is injected or otherwise introduced into the combustion chamber, preferably sufficiently early that it becomes at least substantially homogeneously dispersed within the chamber before a subsequent injection is made. One or more subsequent injections of higher-reactivity fuel charges are then made, and these preferably distribute the higher-reactivity matter within the lower-reactivity chamber space such that combustion begins in the higher-reactivity regions, and with the lower-reactivity regions following thereafter.

Abstract: A compression ignition engine uses two or more fuel charges having two or more reactivities to control the timing and duration of combustion. In a preferred implementation, a lower-reactivity fuel charge is injected or otherwise introduced into the combustion chamber, preferably sufficiently early that it becomes at least substantially homogeneously dispersed within the chamber before a subsequent injection is made. One or more subsequent injections of higher-reactivity fuel charges are then made, and these preferably distribute the higher-reactivity matter within the lower-reactivity chamber space such that combustion begins in the higher-reactivity regions, and with the lower-reactivity regions following thereafter.

Abstract: A first fuel charge having low reactivity (low cetane number) is injected into a rotary engine, e.g., a Wankel engine, sufficiently early during the intake stroke that a subsequent higher-reactivity injected fuel charge forms one or more stratified high-reactivity regions within the engine chamber. Compression ignition then begins at the high-reactivity regions and propagates to the lower-reactivity regions. Appropriate choice of the timings, quantities, and other parameters of the injections can allow control of the timing and rate of combustion, such that work output can be maximized, unburned fuel can be minimized, and chamber temperature can be controlled to reduce heat losses and NOx emissions. As a result, rotary engine efficiency can be enhanced while emissions are reduced. Since the invention can be implemented in a lightweight and compact rotary engine, it is well suited for use in hybrid and compact vehicles.

Abstract: A compression ignition (diesel) engine uses two or more fuel charges during a combustion cycle, with the fuel charges having two or more reactivities (e.g., different cetane numbers), in order to control the timing and duration of combustion. By appropriately choosing the reactivities of the charges, their relative amounts, and their timing, combustion can be tailored to achieve optimal power output (and thus fuel efficiency), at controlled temperatures (and thus controlled NOx), and with controlled equivalence ratios (and thus controlled soot). At low load and no load (idling) conditions, the aforementioned results are attained by restricting airflow to the combustion chamber during the intake stroke (as by throttling the incoming air at or prior to the combustion chamber's intake port) so that the cylinder air pressure is below ambient pressure at the start of the compression stroke.

Abstract: A compression ignition engine uses two or more fuel charges having two or more reactivities to control the timing and duration of combustion. In a preferred implementation, a lower-reactivity fuel charge is injected or otherwise introduced into the combustion chamber, preferably sufficiently early that it becomes at least substantially homogeneously dispersed within the chamber before a subsequent injection is made. One or more subsequent injections of higher-reactivity fuel charges are then made, and these preferably distribute the higher-reactivity matter within the lower-reactivity chamber space such that combustion begins in the higher-reactivity regions, and with the lower-reactivity regions following thereafter.

Abstract: A combustion chamber valve, such as an intake valve or an exhaust valve, is briefly opened during the compression and/or power strokes of a 4-strokes combustion cycle in an internal combustion engine (in particular, a diesel or CI engine). The brief opening may (1) enhance mixing withing the combustion chamber, allowing more complete oxidation of particulates to decrease engine emissions; and/or may (2) delay ignition until a more desirable time, potentially allowing a means of timing ignition in otherwise difficult-to-control conditions, e.g., in HCCI (Homogeneous Charge Compression Ignition) conditions.

Abstract: A combustion chamber valve, such as an intake valve or an exhaust valve, is briefly opened during the compression and/or power strokes of a 4-stroke combustion cycle in an internal combustion engine (in particular, a diesel or CI engine). The brief opening may (1) enhance mixing withing the combustion chamber, allowing more complete oxidation of particulates to decrease engine emissions; and/or may (2) delay ignition until a more desirable time, potentially allowing a means of timing ignition in otherwise difficult-to-control conditions, e.g., in HCCI (Homogeneous Charge Compression Ignition) conditions.

Abstract: A combustion chamber valve, such as an intake valve or an exhaust valve, is briefly opened during the compression and/or power strokes of a 4-stroke combustion cycle in an internal combustion engine (in particular, a diesel or CI engine). The brief opening may (1) enhance mixing withing the combustion chamber, allowing more complete oxidation of particulates to decrease engine emissions; and/or may (2) delay ignition until a more desirable time, potentially allowing a means of timing ignition in otherwise difficult-to-control conditions, e.g., in HCCI (Homogeneous Charge Compression Ignition) conditions.