Lightweight, Diesel Fueled Rotary Engine for Mobile Power

Period of Performance: 03/19/1998 - 03/19/2000


Phase 2 SBIR

Recipient Firm

Moller International, Inc.
1222 Research Park Dr
Davis, CA 95616
Principal Investigator

Research Topics


The DoD's desire for a small, lightweight engine that operates on heavy fuel can be satisfied by a charge cooled rotary engine utilizing a unique stratified charge combustion process. Curtiss-Wright and John Deere have previously demonstrated operation with a stratified charge combustion process that utilized direct fuel injection with spark ignition. Previous work done by Moller International demonstrated that the process could be duplicated using a much lower cost approach. Moller International has made the commitment to add the diesel powered, industrial rotary engine to their line of production gasoline rotary engines. This program shall significantly accelerate the process. The SBIR program goal for engine performance with respect to weight-to-power ratio of 2 lb/Hp has been successfully met under Phase I. The goal for fuel consumption of 0.45 lb/Hp-hr for engines under 20 Hp has been demonstrated to within 15%. Moller International is confident that the fuel efficiency goals can be exceeded under Phase II by various methods of improving the Brake Mean Effective Pressure (BMEP). These include 1) optimization of the rotor pocket shape, size, and position; 2) application of Moller's patented thermal barrier coating process; and 3) the introduction of low-pressure fuel injection to enhance intake charge stratification. BENEFITS: Phase I of the proposed research demonstrated that a small lightweight rotary engine can satisfy the DoD's requirements for mobile power generation. With the completion of Phase II, a final design shall be available for production for military and commercial use. Two plans are currently in place for the production of the gasoline version of the engine. Since the modifications required to convert rotary engines from gasoline to heavy fuels are modest, these production plans should ensure the government and private sector availability of the engine.