Applications Engineering: Variable Positive Displacement Supercharged Diesel Engine

SOCOM needs powerplants that can combine the power density of gasoline fueled engines with the lowered fire hazard and logistical simplicity of Diesel fueled engines. The primary application is an outboard motor with a nominal rating of 55 hp. This engine also has applications for ultralight aircraft, marine and other platforms throughout the military. There are no commercially available products, foreign or domestic, that meet this specification. VAIREX proposes to use their proprietary Variable Positive Displacement Supercharger (VPDS) to increase the power density of a small (20-25 hp) industrial Diesel by raising the engine's inlet pressure ratio from 3.5 to 4.0, in addition to increasing the operating speed to 4200 rpm. Power densities over 0.40 hp/lb should be achievable at a 1,000 hour design life. This VPDSupercharged Diesel engine will be integrated into a domestically manufactured outboard "lower end" in Phase II. The Phase I SBIR tasks include Product Definition, Engine Selection, and a Supercharger Evaluation Test. Commercial products based on technological spin-offs from this program include Diesel APUs for Hybrid Electric Vehicles, air management systems for vehicular fuel cell power systems and small displacement superchargers for the automotive industry.