Abstract: A dual-fluid injection system for an internal combustion engine, and an unmanned aerial vehicle (UAV) powered by an engine having the dual-fluid injection system. The dual-fluid injection system comprises a liquid fuel metering device and a fluid delivery device operating in tandem. A gas supply system comprising an air compressor and an air delivery path extending between the air compressor and the fluid delivery device is provided to supply pressurised air to the fluid delivery device. The gas supply system comprises an air compressor and an air delivery path extending between the air compressor and the fluid delivery device. A fuel supply system is adapted to deliver liquid fuel to the liquid fuel metering device. A fuel-air regulator is provided for regulating fuel pressure with reference to air pressure to establish and maintain a requisite pressure differential between the fuel pressure and the air pressure.

Abstract: A compact muffler (40) for an engine exhaust system, which is particularly applicable for use with small, reciprocating piston two-stroke engines of the type used on unmanned aerial vehicles (UAVs). The compact muffler (40) comprises an exhaust gas flow path (67) between an inlet (61) and an outlet (63). The exhaust gas flow path (67) comprises a plurality of adjacent flow passages (65), wherein at least two of the adjacent flow passages (65) are fluidly connected in series to enable the flow of exhaust gas from one to the other along the flow path (67). The adjacent flow passages (65) are configured for fluid flow therealong in opposed directions. A bypass passage (70) is provided between the two adjacent flow passages (65) for further communication between the two flow passages and to promote an equalisation of fluid pressure within the two adjacent passages (65). A UAV having an internal combustion engine (31) fitted with an exhaust system comprising the compact muffler (40) is also disclosed.

Abstract: A muffler (40) devised particularly for use with an engine of the type used on unmanned aerial vehicles (UAVs), and a UAV (10) having an engine (30) fitted with the muffler (40). The muffler (40) comprises a body (51) having an interior chamber (60). The muffler body (51) has a first end section (53) and a second end section (55). The first end section (51) is adapted for mounting onto the engine (31) by way of a first mount (81), with the interior chamber (60) in communication with an exhaust outlet of the engine (31) to receive exhaust flow therefrom. The second end section (53) is adapted to be mounted by way of a second mount (82) in a manner resisting movement with respect to the engine (31). In one arrangement, the second mount (82) is configured to yieldingly resist movement with respect to the engine (30). In another arrangement, the second mount (82) is configured to mount the second end section (55) under a preload resisting movement of the second end section with respect to the engine (30).

Abstract: A control system and method relating to operation of an internal combustion engine, particularly an engine for powering an unmanned aerial vehicle. The engine has a combustion chamber and a throttle for regulating fluid flow to the combustion chamber, the throttle being operable under the control of an electronic control unit. With the control system and method there are first and second modes optionally available for operation of the engine. In the first mode the engine is operable at a throttle setting set by a request from a first remote controller (e.g. a ground-based controller) via a second on-board controller. In the second mode the engine is operable at a prescribed minimum throttle setting asserted by the electronic control unit which limits the authority of the on-board controller. The engine is caused to operate in the second mode if a particular throttle setting determined from a request of the remote controller is less than the prescribed minimum throttle setting.

Abstract: A method and system for controlling operation of an internal combustion engine of a vehicle (such as a remotely operable unmanned aerial vehicle) to perform or implement a control strategy for controlling operation of the engine. The method and system comprises providing first and second modes optionally available for operating the engine, and changing operation of the engine from the first mode of operation to the second mode of operation following a determination that a characteristic of the operation of the engine (such as engine speed) has been requested to be modified to beyond a predetermined threshold or level. The method and system further comprises reverting control of operation of the engine from the second mode to the first mode once the requested characteristic is no longer beyond the predetermined threshold or level.

Abstract: An unmanned aerial vehicle has an internal combustion engine, and a fuel and lubrication system comprising a fuelling system for fuelling the engine and a lubrication system for delivering lubricating oil to the engine. The fuelling system comprises a fuel reservoir from which fuel can be delivered to the engine. The fuel reservoir comprises a main tank and a header tank. The lubrication system comprises an oil tank. The oil tank is accommodated internally within the main tank to provide an integrated assembly. The arrangement provides for warming of lubrication oil for the UAV engine using several available heat sources. Further, the arrangement facilitates a configuration and layout intended to minimise or negate any undesirable moments of inertia for the UAV during flight as fuel and oil is consumed.

Abstract: A control system and method relating to operation of an internal combustion engine, particularly an engine for powering an unmanned aerial vehicle. The engine has a combustion chamber and a throttle for regulating fluid flow to the combustion chamber, the throttle being operable under the control of an electronic control unit. With the control system and method there are first and second modes optionally available for operation of the engine. In the first mode the engine is operable at a throttle setting set by a request from a first remote controller (e.g. a ground-based controller) via a second on-board controller. In the second mode the engine is operable at a prescribed minimum throttle setting asserted by the electronic control unit which limits the authority of the on-board controller. The engine is caused to operate in the second mode if a particular throttle setting determined from a request of the remote controller is less than the prescribed minimum throttle setting.

Abstract: A method and system for controlling operation of an internal combustion engine of a vehicle (such as a remotely operable unmanned aerial vehicle) to perform or implement a control strategy for controlling operation of the engine. The method and system comprises providing first and second modes optionally available for operating the engine, and changing operation of the engine from the first mode of operation to the second mode of operation following a determination that a characteristic of the operation of the engine (such as engine speed) has been requested to be modified to beyond a predetermined threshold or level. The method and system further comprises reverting control of operation of the engine from the second mode to the first mode once the requested characteristic is no longer beyond the predetermined threshold or level.

Abstract: An unmanned aerial vehicle has an internal combustion engine, and a fuel and lubrication system comprising a fuelling system for fuelling the engine and a lubrication system for delivering lubricating oil to the engine. The fuelling system comprises a fuel reservoir from which fuel can be delivered to the engine. The fuel reservoir comprises a main tank and a header tank. The lubrication system comprises an oil tank. The oil tank is accommodated internally within the main tank to provide an integrated assembly. The arrangement provides for warming of lubrication oil for the UAV engine using several available heat sources. Further, the arrangement facilitates a configuration and layout intended to minimise or negate any undesirable moments of inertia for the UAV during flight as fuel and oil is consumed.

Abstract: An air cooling system for an unmanned aerial vehicle including a propeller (14) driven by an engine (12) has at least one cooling air duct (22) to direct cooling air to cool a vehicle component e.g. a cylinder head. The duct has at least one air inlet and at least one air outlet. Operation of the propeller causes a pressure differential between the air outlet (24,124) and the air inlet (23,123) which draws air through said cooling air duct (22). A cowling (16) can cover at least part of the engine, and can form a plenum and have the supply of cooling air through a front face aperture (164) or side walls (17) of the engine cowl (16).

Abstract: For an unmanned aerial vehicle (UAV) engine, an exhaust gas temperature control method is provided during operation of the UAV engine to protect exhaust components, particularly lightweight aluminium components, from overheating or melting. The engine is operated with a leaner than stoichiometric air-fuel ratio during low or part engine load conditions. Transition to a richer than stoichiometric air-fuel ratio is made as engine load or engine speed, or both engine load and engine speed, increase(s). At sufficiently low engine loads, the air-fuel ratio can be maintained in a lean ratio region. As demand on the engine causes engine speed and load to increase, the amount of excess air available reduces. The ability to operate lean is reduced and the exhaust gas temperature increases as the mixture becomes richer. In order to obtain the demand power, and keep exhaust temperature below an exhaust gas temperature limit, the air-fuel ratio is transitioned to a richer than stoichiometric region.

Abstract: An unmanned aerial vehicle (UAV) engine (40) lubrication system and lubrication oil heating strategy uses a solenoid actuated electric oil pump (10,42) to deliver lubrication oil to the engine from a lubrication oil reservoir (12,44) by energizing and de-energizing the solenoid (18) to operate a pump mechanism of the electric oil pump. A controller (ECU) (100) can control operation of the electric oil pump, the solenoid maintained energized for a required period of time to cause heating of the oil without continuously pumping the oil. An electric oil pump control strategy can maintain engine speed dependent minimum oil delivery rates, can heat the electric oil pump and oil through extended energized (ON) time of the solenoid, and, by varying the turn on time of the electronic oil pump based on sensed ambient temperature, long time periods can be used to ensure oil delivery for cold temperatures, and shorter times are permitted when necessary in order to reach maximum oil flow rate.

Abstract: For an unmanned aerial vehicle (UAV) engine, an exhaust gas temperature control method is provided during operation of the UAV engine to protect exhaust components, particularly lightweight aluminium components, from overheating or melting. The engine is operated with a leaner than stoichiometric air-fuel ratio during low or part engine load conditions. Transition to a richer than stoichiometric air-fuel ratio is made as engine load or engine speed, or both engine load and engine speed, increase(s). At sufficiently low engine loads, the air-fuel ratio can be maintained in a lean ratio region. As demand on the engine causes engine speed and load to increase, the amount of excess air available reduces. The ability to operate lean is reduced and the exhaust gas temperature increases as the mixture becomes richer. In order to obtain the demand power, and keep exhaust temperature below an exhaust gas temperature limit, the air-fuel ratio is transitioned to a richer than stoichiometric region.

Abstract: An unmanned aerial vehicle (UAV) engine (40) lubrication system and lubrication oil heating strategy uses a solenoid actuated electric oil pump (10,42) to deliver lubrication oil to the engine from a lubrication oil reservoir (12,44) by energising and de-energising the solenoid (18) to operate a pump mechanism of the electric oil pump. A controller (ECU) (100) can control operation of the electric oil pump, the solenoid maintained energised for a required period of time to cause heating of the oil without continuously pumping the oil. An electric oil pump control strategy can maintain engine speed dependent minimum oil delivery rates, can heat the electric oil pump and oil through extended energised (ON) time of the solenoid, and, by varying the turn on time of the electronic oil pump based on sensed ambient temperature, long time periods can be used to ensure oil delivery for cold temperatures, and shorter times are permitted when necessary in order to reach maximum oil flow rate.

Abstract: An air cooling system for an unmanned aerial vehicle including a propeller (14) driven by an engine (12) has at least one cooling air duct (22) to direct cooling air to cool a vehicle component e.g. a cylinder head. The duct has at least one air inlet and at least one air outlet. Operation of the propeller causes a pressure differential between the air outlet (24,124) and the air inlet (23,123) which draws air through said cooling air duct (22). A cowling (16) can cover at least part of the engine, and can form a plenum and have the supply of cooling air through a front face aperture (164) or side walls (17) of the engine cowl (16).

Abstract: A method of lubricating and cleaning a fuel injector of a fuel injection system of an internal combustion engine during running of the engine including delivering both a lubricant and a cleaning additive to the injector. The injector injects directly into the combustion chamber of the engine. The lubricant and cleaning additive are delivered to the fuel exit area of the injector.

Abstract: An air charging device is connected to a supply tank, a pump and a use facility, such as a faucet. When the faucet is opened, water flow from the tank through the device to the faucet charges a chamber in the device with air; while when the pump is actuated, water flow from the pump through the device to the tank causes the air in the chamber to be compressed and escape into the tank. The flow of water in either of two directions causes a freely movable valve member to engage and shift a plunger. Movement of the plunger in one direction causes intake of air into the chamber, and movement thereof in the other direction causes compression and discharge of air into the supply tank.