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A low cost multipoint fuel injection system which utilises no-moving-part fluidic devices as fuel injectors for gasoline engines is presented in this paper. This unique fluidic injector unit consists of four monostable fluidic devices, four air-fuel mixing nozzles and a prototype solenoid pulser interface for switching the fluidic stages. The current Electronic Fuel Injection (EFI) systems are reviewed and features of the fluidic injection system are illustrated in this paper. Preliminary investigation on the operating characteristics of the prototype unit was carried out both on a laboratory rig and on an engine test bench. The improvement in air/fuel mixture preparation by the fluidic fuel injection system compared with a baseline carburettor has been demonstrated.

A prototype multipoint fuel injection system which utilises fluidic injection devices as fuel injectors for spark ignition engines is described in this paper. The unique fluidic injector unit combines four no-moving-part, monostable fluidic devices controlled by a solenoid valve interface and air-fuel mixing nozzles for well atomised air-fuel mixture. The design philosophy and operating characteristics of the novel integrated fluidic injector unit for engine applications are discussed in details in this paper. The initial engine tests on this fluidic injection system show that it provides an extended lean limit of the air/fuel mixture (by 2.2 air/fuel ratio), 7% improvement in fuel economy and 10% reduction in HC emissions compared with a base line carburetted system. These results confirmed that the use of the fluidic fuel injection system resulted in improved fuel distribution, better air/fuel mixture preparation and faster flame propagation speed.

This paper describes a gasoline injection system based on air-assisted fluidic injectors. This injection system was implemented on a research engine and the results of air to fuel ratio (AFR) variations, engine combustion characteristics and exhaust emissions from the fluidic injector unit were compared with those from the baseline solenoid type injector. It was demonstrated that the fluidic system produces 9% to 20% lower HC emissions and 5% to 8% higher IMEP than the baseline injection system. This has confirmed the effectiveness of the use of the air-assisted fluidic injector stages and that the improved mixture preparation fuel presentation are obtained by the fluidic system. However, the cyclic flow stability of the fluidic device needs improvement.

A novel gas fuel injector system based on the use of monostable fluidic devices is described in this paper. The proposed system consists of non-moving-part fluidic devices which are capable of operating in a Pulse Width Modulated (PWM) control mode and of handling a large amount of gas flow for engine operations. The system also includes an electro-fluidic interface for fluidic switching and air-gas mixing nozzles for better mixing quality. Two prototype fluidic injector units were produced and their steady-state and dynamic characteristics were evaluated on a laboratory test rig. The results were compared with those from several commercial gas injectors and it was found that the fluidic injector has a faster dynamic response and a smaller cycle-cycle variations.