Unmanned Systems Technology 026 I Tecdron TC800-FF I Propellers I USVs I AUVSI 2019 part 1 I Robby Moto UAVE I Singular Aircraft FlyOx I Teledyne SeaRaptor I Simulation & Testing I Ocean Business 2019 report

71 Robby Moto UAVE | Dossier manufacturing simplicity. Extensive CFD studies were carried out to optimise for air-fuel flow and exhaust flow around these parameters by Marco Costa. He modelled the fluid dynamics using a combination of TopSolid 3D, STAR- CCM+ and STAR-ICE, an add-on to STAR-CCM+ developed in 2017 for in- cylinder simulations. For operating and timing the valvetrain, the crankshaft’s distribution gear drives the main timing gear, and the latter has roughly twice the circumference of the former in order to turn each camshaft once for every two crank rotations. A pair of shafts extend from the front and back of the main timing gear. Each has a sprocket mounted to drive one end of the steel timing chain, and the other end of the timing chain drives a sprocket on the back end of the camshaft, with one camshaft in each of the two banks. The tension and positioning of each timing chain is maintained by two pairs of thermoplastic tensioner shoes, which are installed in the top and bottom of the chamber and run between the distributor and the cams. “The cam doesn’t act directly on the valve, and we don’t use pushrods,” Costa explains. “The cam lobes act directly on the rocker arms, and they push the valve stems down, to give the valvetrain a small overall footprint in the cylinder head and to keep the engine width compact.” Marino adds, “The UAVE’s cam profile is completely different from that of the RES, to help the UAVE ‘breathe’ better and obtain its peak power at 5000 rpm instead of 4000 rpm. For example, the UAVE has a sharper acceleration for the valves’ openings and closings, which is enabled by changing the cam lobe shape. “Also, the RES’ intake valve lift is 8 mm and its exhaust valve lift is 7.5 mm, whereas the UAVE’s intake valve lift is 8.4 mm and the exhaust valve lift is 7.7 mm.” Each cylinder has a single 8 mm spark plug, with a coil manufactured by ACDelco and supplied by EFI Technology, using an inductive discharge ignition system. “In a four-stroke engine you have a spark every two rotations, and its Unmanned Systems Technology | June/July 2019 Robby Moto UAVE Boxer type Stroke: 72.0 mm Bore: 61.4 mm Displacement: 499.98 cc Gasoline fuel, RON 95+ Naturally aspirated Aluminium alloy structure Linerless with case hardening treatment Three main bearings, plain Steel crankshaft, three sections, two pins Steel monolithic con rods Aluminium pistons, three rings Two valves per cylinder One plug per cylinder Port injected Liquid cooled Engine management system 14:1 compression ratio Maximum rpm, 8000 Some key suppliers Castings for crankcase, heads, and other parts: SBA Pozzato Machining for crankcase, heads, and other parts: in-house Bore coating: Cylinder Line Crankshaft: in-house Camshafts: in-house Con rods: in-house Oil pan: in-house Tappets: in-house Rockers: in-house Pistons: Pistal Racing Rings: Pistal Racing Piston pins: Pistal Racing Circlips: Pistal Racing Valves: Scarpa & Colombo Valve seats: in-house Valve springs: Mollificio Legnanese Gaskets: Lariete Ignition system: EFI Technology Spark plugs: NGK Fuel injectors: Bosch Engine management system: EFI Technology Sensors: Bosch Data acquisition: AIM Electronic boards: EFI Technology Wiring: EFI Technology Throttle: Bosch Oil pumps: in-house Oil filter: UFI Alternator: Ducati Energia Airbox: in-house Intake manifold: in-house Wiring loom: EFI Technology Propeller: GT Tonini Voltage regulator: Ducati Energia Oil: Motul Surface treatments: SET Surface treatments: Lafer Heat treatments: SET Metals: TAU Metalli Metals: SCAM Dynos: Borghi Saveri Machine tools: Mazak QC equipment: Mitutoyo Design software: TopSolid 7 Testing software: Midas NFX Testing software: Abaqus CAE Datasheet