SBIR-STTR Award

Fundamentally, increasing engine power density, without an associated increase of engine speed, requires increasing the brake mean effective pressure (BMEP) as high as practical. Achieving the highest possible peak cylinder pressure, compatible with engine structural capability and desired life in order to obtain high power and goo fuel economy, requires innovative approaches in fuel injection system and combustion enhancement rechniques. One of the approaches is to allow combustion to continue much later into the expansion stroke. This increases the BMEP without an accompanying increase in exhaust temperature, particulate emissions and smoke. Potential technologies to accomplish these objectives include ultr-high injection pressure, ijection rate control and/or split injection, combustion chamber and air-charge manaegment, are identified. Multiple injectors per cylinder is anticipated to increase fuel quantity and to control injection rate within the reduced duration limits. Each of these technologies has its own important parameters effecting engine efficiency and exhaust emissions formation. The greatest challenge of this project is identifying optimum settings and viable solutions by searching for small improvements from a large number of parameters. Using the proven Servojet electrohydraulic fuel injection system and advnaced fuel ijection simulation software, BKM will concentrate on development and integration of the injection characteristics of the ultra-high pressure fuel injection system. Performance characteristics of an advanced fuel injection system shall be provided and subtantiated by analytical calculations, computer simulations and predictions.

Keywords:
ULTRA-HIHG INJECTION PRESSURE INJECTION RATE-SHAPED FIS CFD COMMON-RAIL COMBUSTION DURATION

Project objective is to prove a concept of increasing engine power density. Ultrahigh pressure fuel injection is chosen as an approach to enhance fuel/air mixing rate, to decrease or eliminate ignition delay and to increase burning rate; resulting in improved air utilization. In this way, fuel/air mixture becomes richer, approaching stoichiometric, resulting in linear increase in engine BMEP. Electronically controlled, common rail injection system with 2500 bar peak pressure is anticipated. Phase II work plan assumes building a prototype, bench test and single cylinder engine test. 3D computations for in cylinder analysis using improved Kiva3 code, PDPA spray characterization and FIS simulation are proposed as analytical-predictive methods. An additional option for injection/combustion system is proposed (OSKA-S) It consists of a single spray impinging on the piston target with a unique mixture formation combined with ultrahigh injection pressure electronic system with falling injection rate. If successful, project will result in the prototype of an advanced fuel injection system and demonstrate increased engine power density by burning richer mixture with higher thermal efficiency. Ultrahigh injection pressure fuel system will be designed, fabricated and tested. Increased engine power density will be demonstrated. Predictive capabilities of KIVA code for 3D in-cylinder combustion analysis will be improved. Advanced fuel injection system and increase engine BMEP is also beneficial for commercial applications.

Keywords:
Diesel Engine Pdpa High Power Density Oska Ultrahigh Injection Pressure Injection Kiva