Abstract: Torsional vibration is one of the critical areas of shafting vibration. Multi-harmonic fluctuations from the output torque of an engine, propeller, or other power sources constitute the main source of torsional vibration of a shafting system, and stimulate other coupled vibrations. Torsional dampers have been the main coutermeasure to deal with torsional vibration. However, with the increasing requirements for vibration and noise reduction, such traditional method has exposed obvious shortcomings. People have been researching for new technological methods, but seem to be in lack of significant breakthroughs. We attempts to Innovatively propose an systematical solution by both software and hardware. This paper introduces a new method to address torsional vibrations of shafting systems based on line spectrum active control. A multi-body dynamic analysis model is used to reveal the coupling characteristics of torsional vibration and vibration in other directions. In addition, a new cross-coupled multi-channel line spectrum active control algorithm is proposed alongside a new type of torque actuator where the internal electromagnetic structure contains a rotating stator and rotor. These components are connected with springs, and the whole assembly can rotate with the shafting. The dynamic torque is issued according to the command of the active control system in order to suppress the torque fluctuation caused by the power sources, which in turn greatly reduces the torsional vibration of the shafting.
Abstract: Torsional vibration is one of the critical areas of shafting vibration. Multi-harmonic fluctuations from the output torque of an engine, propeller, or other power sources constitute the main source of torsional vibration of a shafting system, and stimulate other coupled vibrations. Torsional dampers have been the main coutermeasure to deal with tor...Show More
Abstract: This study aims to select a twin-engine multirole fighter employing multiple criterion decision-making analysis (MCDMA) technique. In this process, competing goals and objectives must be balanced, especially when it comes to the price of purchasing, maintaining, and updating the fleet. Deciding on the many possibilities accessible can be efficiently assisted by multiple criterion decision-making analysis methodologies. The subject-specific literature was consulted to develop the selection criteria, and the analysis technique is utilised to ascertain the optimal planning methodology for defence procurement and fleet upgrades in addition to which fighter aircraft should be purchased for the air defence force. The research project explores subject-specific literature in search of strong selection criteria, guaranteeing a thorough basis for assessment. The analysis technique used not only helps identify the best planning approach for defense acquisitions and fleet modernizations, but it also supports the critical choice of which fighter aircraft is best suited for the air defense force. This study adds to the strategic framework guiding defense procurement by highlighting the need for a comprehensive approach in selecting a twin-engine multirole fighter that aligns with a variety of operational requirements and budgetary considerations. It does this by combining literature insights with advanced decision-making methodologies. Overall, the aim is to make an informed and strategic decision that will benefit the air force in the long run. The purpose of this work is to provide a method for evaluating the fighter aircraft alternatives DassaultRafale, Eurofighter Typhoon, FA18 Super Hornet, Mig-35, Su-35, and F-15EX based on a technique for order preference by the resemblance to the ideal solution (TOPSIS).
Abstract: This study aims to select a twin-engine multirole fighter employing multiple criterion decision-making analysis (MCDMA) technique. In this process, competing goals and objectives must be balanced, especially when it comes to the price of purchasing, maintaining, and updating the fleet. Deciding on the many possibilities accessible can be efficientl...Show More