Adaptive, semiactive model simulation of the mountingof an aeroplane's piston engine

• Autorzy: Jeż M.
• Konferencja: Proceedings of the Third Seminar on Recent Research and Design Progress in Aeronautical Engineering and its Influence on Education/seminar(III; 23-25.11.1998; Warszawa, Polska)
• Języki publikacji: EN

Abstrakty

EN

Subject of this paper is the deterministic, nonlinear model of engine mounting (suspension). Numerical investigation of dynamic behaviour and simulation of aeroplane operational regimes were carried out. The six-dimensional model with progressive stiffness and sub-viscous damping was examined in the Matlab-Simulink environment. The model responses were analysed in time and frequency domains, also in phase space. Between contemporary propulsion units of light aeroplanes the piston engines with small number of opposed-cylinders are the most troublesome from dynamic point of view. They generate poli-harmonic exciting moment as the result of sequential character of its thermodynamic operations and the transformation of reciprocal into rotational motion. The vibroisolation of engine with elasto-damping suspension is the investigation subject of numerous R&D teams. There are procedures for avoiding resonances in working range of parameters space. But all passive vibroisolation schemes are condemned to compromise. That is why the active approach is becoming more interesting. The engine suspension model exhibits weak couplings of body rotation with other degrees of freedom, so only the excited mode's active vibroisolation was examined. During engine RPM variation the exiting harmonics frequency changes - proposed semi-active system must suspension natural frequencies accordingly to spectrum of exciting torque. The aim to achieve, by maintaining constant ratio of exciting to natural system's frequency, is the minimum of forces transmitted to the plane structure in the damped system. Verification of higher efficacity of active suspension design, in comparison with the passive was made by registration of resulting body displacements. During chirp, monoharmonic and poll- excitations 2-5 times vibration reduction was obtained. The supremacy of active suspension scheme was concluded also in frequency domain - the maxima about ten-fold smaller in adaptive suspension than those observed in the passive one.

Słowa kluczowe

EN

piston engines; aircrafts; simulation model

PL

silniki tłokowe; samoloty; modele symulacyjne

• Wydawca: Institute of Aeronautics and Applied Mechanics, Warsaw University of Technology
• Czasopismo: Research Bulletin / Warsaw University of Technology, Institute of Aeronautics and Applied Mechanics
• Rocznik: 1999
• Tom: nr 9
• Strony: 23--26
• Opis fizyczny: Bibliogr. 7 poz., rys., wykr.

Twórcy

autor

Jeż M.

• Institute of Aeronautics, Warsaw, Poland