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The purpose of this paper is to present results of practical experience of cold starting a gasoline engine on low volatility fuel suitable for unmanned aerial vehicle (UAV) deployment.

Experimental research and development is carried out via dynamometer testing of systems capable of achieving cold start of a spark ignition UAV engine on kerosene JET A-1 fuel.

Repeatable cold starts have been satisfactorily achieved at ambient temperatures of 5°C. The approximate threshold for warm engine restart has also been established.

For safety and supply logistical reasons, the elimination of the use of gasoline fuel offers major advantages not only for UAVs but also for other internal combustion engine-powered equipment to be operated in military theatres of operation. For gasoline crankcase-scavenged two-stroke cycle engines, this presents development challenges in terms of modification of the lubrication strategy, achieving acceptable performance characteristics and the ability to successfully secure repeatable engine cold start.

The majority of UAVs still operate on gasoline-based fuels. Successful modification to allow low volatility fuel operation would address single fuel policy objectives.

This paper aims to conduct an experimental and theoretical investigation into fuel pre-delivery effects for a heavy fuel crankcase scavenged spark ignition two-stroke cycle engine for unmanned aerial vehicle application.

One-dimensional computational fluid dynamic modelling of the engine system using WAVE software supported by experimental dynamometer testing of the subject engine with kerosene JET A-1 and gasoline and fuels.

The experimental research has shown performance improvements using fuel preheating via use of auxiliary transfer port fuel injection. Computational simulation has allowed comparisons with auxiliary transfer port injection and direct in-cylinder injection to be made.

While some heavy fuel engines are now available for unmanned aerial vehicles the best solution to meet the military equipment single fuel policy remains an area of evolving research. The findings within this study show possibilities for fuel pre-treatment.

One-dimensional computational fluid dynamic modelling of the engine system using WAVE software supported by experimental dynamometer testing of the subject engine with kerosene JET A-1 and gasoline fuels.

This paper aims to present experimental experience of heavy fuelling of a spark ignition crankcase scavenged two-stroke cycle unmanned aerial vehicle (UAV) engine, particularly focusing on the effects of compression ratio variation, and to cross-correlate with the results of fluid dynamic modelling of the engine and fuels used.

One-dimensional modelling of the engine has been conducted using WAVE software supported by experimental dynamometer testing of a spark ignition UAV engine to construct a validated computational model using gasoline and kerosene JET A-1 fuels.

The investigation into the effects of compression ratio variation via fluid dynamic simulation and experimental testing has allowed an assessment of the approach for improving heavy fuel operation of UAV engines using auxiliary transfer port fuel injection. The power level achieved with reduced compression ratio heavy fuel operation is equal to 15.35 kW at 6,500 revolutions per minute compared to 16.27 kW from the standard gasoline engine or a reduction of 5.7%.

The studied engine is specifically designed for UAV applications. The validation of the computational models to explore the effects of compression ratio and heavy fuel injection on the solution and cost is supported by experimental tests.

The application of auxiliary port fuel injection of heavy fuel and associated compression ratio optimisation offers an alternative approach to achieve the safety and logistical challenges of the single fuel policy for UAVs. The application of WAVE to simulate crankcase scavenged two-stroke cycle engines has been applied in very few cases. This study shows further exploratory work in that context.

This paper aims to present experimental results of gasoline-fuelled engine operation of a crankcase-scavenged two-stroke cycle engine used for unmanned air vehicle (UAV)/unmanned air system application and to cross correlate with computational fluid dynamic modelling results.

Computational modelling of the engine system was conducted using the WAVE software supported by the experimental research and development via dynamometer testing of a spark ignition UAV engine to construct a validated computational model exploring a range of fuel delivery options.

Experimental test data and computational simulation have allowed an assessment of the potential advantages of applying direct in-cylinder fuel injection.

The ability to increase system efficiency offers significant advantages in terms of maximising limited resources and extending mission duration capabilities. The computational simulation and validation via experimental test experience provides a means of assessment of possibilities that are costly to explore experimentally and offers added confidence to be able to investigate possibilities for the development of similar future engine designs.

The software code used has not been applied to such crankcase-scavenged two-stroke cycle engines and provides a valuable facility for further simulation of the twin cylinder horizontally opposed design to offer further system optimisation and exploration of future possibilities.

The SPV580 stepped piston engine has been designed and developed for UAV application. The gasoline engine produces a minimum of 30kW at 5000 RPM, increasing to 35.4kW if exhaust tuning can be permitted. The gasoline performance of this novel engine design is presented together with work to investigate the feasibility and performance characteristics of kerosene fuelling.

What happens to export markets when the nations in which customers reside experience a sudden, unanticipated change in a relevant aspect of the environment? Which goods exported to these nations tend to be affected more than others? The study reported in this paper examines the impact that the oil shock of the 1970s had on world export markets. This sudden environmental change caused some nations to obtain sudden wealth and others to experience instant economic problems. The findings of the study illustrate the range of consequences for export markets that can occur, depending on the manner in which nations are affected by sudden change.