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Aircraft Security
Published in Stephen J Wright, Aviation Safety and Security, 2021
The weight, or more correctly, the mass of the aircraft must be overcome by the lift generated by wings, so if the aircraft is unable to reach sufficient forward speed to create sufficient lift, the plane does not take off. It is this mass-limiting balance that aircraft designers have addressed, even from the earlier days of flight. Early powered aircraft used technologies developed in fabric-covered ultra-lightweight rowing boats, coupled with a motorcycle engine, to allow for powered flight. Typically, the militarisation of new aircraft technology has allowed these small aircraft to develop further, to fly faster, higher and to carry more mass (e.g. fuel, bombs, passengers, etc.). All of the aforementioned mass limitations have been addressed effectively since the end of the First World War, and the ongoing development of high bypass turbine engines has resulted in much greater engine performances.
Vibration Control
Published in Haym Benaroya, Mark Nagurka, Seon Han, Mechanical Vibration, 2017
Haym Benaroya, Mark Nagurka, Seon Han
Vibration Perceived as Power. Vibration is often perceived as power. If a machine vibrates significantly, it may be viewed as being powerful. But, this commonly held view is perception only. It is certainly possible through good design (such as using passive and active control) to make higher power machines vibrate less than lower power machines. The perception that more vibration equals more power is often exploited by marketing and sales teams. It explains the commercial success of motorcycles, for example, that are loud and shake significantly. A motorcycle engine that is well balanced with appropriate mufflers may indeed be more powerful than a shaky, loud engine, even if the consumer is not convinced. The design of powered hand tools is also affected by this issue of perception. It is possible to design a powered hand tool, such as a reciprocating saw, with advanced anti-vibration features that isolate the action-reaction forces from the user, making it less fatiguing and easier to control, and quiet, also making it less fatiguing to use. High-end designs of powered hand tools have been made that are more powerful and shake much less than typical designs. Some workers may perceive that these tools that are quieter and shake less are less powerful. Balancing tool performance and low vibration is critical for user acceptance, which is often based on perception.33
Transmission
Published in Andrew Livesey, Practical Motorsport Engineering, 2019
The clutch transmits the power from the engine to the gearbox – it must be capable of doing this. Typical clutch modifications include: Operating mechanism – the operating mechanism may be changed – a hydraulic linkage can be set up to provide a better mechanical advantage as well as cope with different clutch positions to that of a cable mechanism.On motorcycle engine systems, such as Suzuki Hybusa and Yamaha R1 engine and gearbox set-ups, the need to disengage the clutch is removed on up changes by having a system that cuts the fuel supply when the gear change is moved. This slows the engine momentarily to allow a smooth clutchless change, saving effort and time.Clutch springs – to transmit the extra torque of a tuned engine the clutch springs will require a higher force when using the same size and type of clutch plate.Clutch spinner plate – for competition purposes a solid spinner plate will be used. This may be of the paddle type for reduced rotating mass – hence quicker gear changes as the speed of rotation can be changed more quickly.Clutch material – a variety of materials are used for clutch friction plates (spinner plates); these include: carbon, ceramic – often sintered to the steel and bronze.
A comprehensive assessment of vehicular performance and emission characteristics during real-time test-runs using selected bio-ethanol–gasoline blends
Published in Biofuels, 2023
Musthafa Babu, Manoj Sivaraman, Thangaraja Jeyaseelan, Asokan MA
An experimental engine study was carried out on a single-cylinder, four-stroke, spark ignition (SI) motorcycle engine (Figure 1) with a displacement capacity of 135 cm3. The test vehicle had a capacitive discharge ignition system for ignition of the air–fuel mixture and a carburetor fuel source. The specifications of the test engine are provided in Table 2. The trials were conducted for all test fuels without any change in the hardware of the vehicle. Some important characteristics, including emission, air consumption and fuel consumption, were tested at varying engine speeds. The temperature of the intake air, ambient air, engine oil and exhaust gas was measured. The engine throttle was adjusted precisely during the tests to ensure maintenance of constant engine speeds within the operating speed conditions from 1000 to 4000 rpm.