Abstract: Embodiments described herein relate to fuel-based heating of intake charge in internal combustion engines. In some aspects, a method of operating a compression ignition engine can include combusting a first fuel in an intake flow path to heat a volume of air. The method further includes drawing the heated volume of air into a plurality of cylinders via an intake manifold and combusting a volume of a second fuel in the plurality of cylinders in a mixing-controlled compression ignition mode (MCCI). The second fuel can be the same or different from the first fuel and can include a small-molecule fuel. Heating the volume of air maintains a temperature in the plurality of cylinders greater than a threshold temperature.

Abstract: Embodiments described herein relate to systems and methods of managing intake temperature of intake gases in internal combustion engines to enable autoignition of small-molecule low-cetane fuels. In some aspects, a method of operating a compression ignition engine can include moving a volume of air through a first flow path, closing a first valve to prevent the volume of air from entering a charge air cooler (CAC), opening a second valve to guide the volume of air to a second flow path, the second flow path including a heating unit, and moving the volume of air to an intake manifold. In some embodiments, the method can further include applying heat via the heating unit to the volume of air while the volume of air moves through the second flow path.

Abstract: According to one embodiment, a reductant injection apparatus includes an injector attachment portion to which a reductant injector is coupleable. The apparatus also includes a perforated tubular portion coupled to the injector attachment portion. The perforated tubular portion includes an inlet, an outlet, and a diverging sidewall extending from the inlet to the outlet. Additionally, a plurality of perforations is formed in the sidewall. A reductant spray can be injected into the perforated tubular portion via the inlet. Further, a portion of a bulk exhaust gas stream can be diverted into the perforated tubular portion through the plurality of perforations, through the perforated tubular element, and out of the perforated tubular portion through the plurality of perforations. The portion of exhaust gas stream can then be rejoined with the bulk exhaust gas stream downstream of the perforated tubular portion.

Abstract: According to one embodiment, a reductant injection apparatus includes an injector attachment portion to which a reductant injector is coupleable. The apparatus also includes a perforated tubular portion coupled to the injector attachment portion. The perforated tubular portion includes an inlet, an outlet, and a diverging sidewall extending from the inlet to the outlet. Additionally, a plurality of perforations is formed in the sidewall. A reductant spray can be injected into the perforated tubular portion via the inlet. Further, a portion of a bulk exhaust gas stream can be diverted into the perforated tubular portion through the plurality of perforations, through the perforated tubular element, and out of the perforated tubular portion through the plurality of perforations. The portion of exhaust gas stream can then be rejoined with the bulk exhaust gas stream downstream of the perforated tubular portion.