The potential of Fluid Dynamic Absorbers for railway vehicle suspensions
Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
The main running objectives concerning the vertical dynamics of passenger rail vehicles are ride comfort and safety. The goal of this thesis is to employ the use of a Fluid Dynamic Absorber to minimize the vertical acceleration of the car body while minimizing the dy-namic force ﬂuctuations in the wheel rail contact. The Fluid Dynamic Absorber is a device which employs a tube with a varying cross section containing oscillating ﬂuid. The device is characterized by two eﬀects: The inertia eﬀect of the oscillating ﬂuid in the varying cross section and the damping eﬀect due to the pressure losses during the ﬂuid ﬂow. It is in-troduced as a potential damping device for automobiles and also for earthquake resistant buildings. The work encompasses the creation of a linearized approximation of the non-linear model for parameter selection. Then, a non-linear model is built with the help of the Modelica language for use in time simulation of quarter-car models in the Dymola interface. A generalized design methodology for the device is then developed with the help of design procedures used for common tuned mass dampers and liquid column dampers. Finally, the non-linear model built using the Dymola interface is also exported for use in the full-car model in Simpack using Functional Mock-up Interface. A reduction of about 4% to 5% in the magnitude of the root mean square of the carbody acceleration was observed while the wheel-rail dynamic forces remained the same. Further improvement possibilities and the parameters inﬂuencing the vertical dynamic behavior of the vehicle are discussed.
Place, publisher, year, edition, pages
2016. , 96 p.
TRITA-AVE, ISSN 1651-7660 ; 2016:81
Engineering and Technology
IdentifiersURN: urn:nbn:se:kth:diva-203815OAI: oai:DiVA.org:kth-203815DiVA: diva2:1082701
DLR Institute of System Dynamics and Control, German Aerospace Centre