Papers by Keyword: Engine Mount

Abstract: The existing Universal Test Bed (UTB) is a facility to ground test Turbojet Engines before installation on the aircraft. This work provides a feasibility study to adapt changes to this UTB for the Turbofan Engine. Necessary design modification of existing UTB is performed by applying propulsive and structural analysis for the adaptation of Turbofan engine. Physical measurements of the UTB and the mounts of Turbofan Engine reveal their mutual compatibility. Based on these measurements, six different CAD models are generated in Solid Works^® and analyzed in ANSYS^® Workbench. After grid independence check, validation of the model with applied loads and the boundary conditions was done through comparison of analytical calculations with those of a simplified CAD model. Based on minimum stress vis-à-vis maximum Factor of Safety (FOS), the best design is finally selected through this research.

Abstract: Vibration exciting theory of working engine was analyzed based on dynamic method. Model of engine system and mounts was established and simulated in multiple working conditions by Power Unit module of dynamics software excite. Vibration acceleration of points on engine block adjacent to each mount was extracted to characterize and evaluate the vibration excited by engine in different working condition.

Abstract: The objective of the powertrain mount design is to find the geometry which meets the desired stiffness and damping requirements. For the conventional rubber mount, which is composed of a rubber element bonded into a metal bracket, its stiffness can be predicted using FEA but the damping is evaluated by physical testing. This paper introduces a design method at which the damping coefficient of the rubber mount is to be predicted theoretically based on the assumption that the phase angle for a rubber compound is constant. Absence of physical test in this proposed new design process, the development time from concept to production is reduced.

Abstract: Study of LMS control method on active engine mount is carried out for ride quality improvement. Take an active engine mount which is based and developed from a hydraulic mount with decoupled disc-membrane as a module, the characteristic of vibration isolation of active engine mount is simulated and analyzed. The results indicated that active engine mount could reduce the vertical vibration effectively with LMS Control method.

Abstract: A MRF fluid engine mount with controlled annular access, inertia track and decoupler is designed. Through the experiment it can be seen that the low frequency performance of the mount is greatly improved. Then the dynamic low frequency performance of the mount using the fuzzy PID control method of two degrees-of-freedom system in different engine speed is simulated and the results show that the fuzzy PID control method is effective to reduce the body acceleration.

Abstract: In order to choose a reasonable isolator component for engine mounting system and to isolate the engine’s vibration effectively, experiments were made on bracket vibration severity of a high power diesel engine. In the experiment, the engine worked at many working performance and used two kinds of isolator component such as rubber-isolator and wire net-isolator. The aims of the experiment were to find the effects of the main vibration excitation on the body; to master the rules of vibration with rotational speed and load; to understand the characteristic and rank of vibration severity when the engine used different isolator and to provide foundations for choosing an effective isolating component. Test showed that the wire-net isolator had better characteristics than that of the rubber isolator. The results have reference value in engine’s further design.

Abstract: Engine mounts are used to isolate the influence of the engine’s vibration on the frame and the body. Both rubber isolator and wire-net isolator are applied as engine mounts. In order to make comparison of their vibration characters correctly, theory of vibration was used to construct a six-degree freedom dynamic model of an engine mount system. Tests were also made on their vibration severity. Calculation and test showed that the dynamic model was correct and feasible. Test was further made on the vibration transfer efficiency of wire-net isolator. The wire-net isolator has better characteristics than that of the rubber isolator. The results have reference value in engine’s further design.

Abstract: In this paper, the theory of DR (Delayed Resonator) is employed to investigate the vibration of vehicles, for the first time, and the process to suppress the vibration transmission from the engine to the body using the DR is explored. A simplified half-car model with DR is built for the case of idling, and the critical time delay is obtained by analyzing the stability of the model, additionally, the different effect of the parameters on the stable region is investigated. Method of solving the optimum values of the gain and the delay for maximum vibration suppression is built, afterwards numerical emulation is carried out to check the effect and to compare with the hydraulic engine mount. The results show that the amplitude of the body can be reduced more effectively.

Abstract: In this paper, vibration control performance of piezostack active engine mount system for unmanned aero vehicle (UAV) is evaluated via computer simulation. As a first step, the dynamic model of engine mount system which is supported at three points is derived. In the configuration of engine mount system, the inertia type of piezostack based active mount is installed for active vibration control. Then, the vibration level of UAV engine is measured. To attenuate the vibration which is transmitted from engine, a sliding mode controller which is robust to uncertain parameters is designed. Vibration control performances of active engine mount system are evaluated at each mount and center of gravity. Effective Control results are presented in both time and frequency domains.