Three Dimensional Vibration Characteristics of High-Speed Automobile Diesel Engine Crankshaft System with a Viscous Fluid Damper

Author(s):  
Tomoaki Kodama ◽  
Katsuhiko Wakabayashi ◽  
Yasuhiro Honda ◽  
Shoichi Iwamoto
2018 ◽  
Vol 763 ◽  
pp. 331-338
Author(s):  
Nikoo K. Hazaveh ◽  
Ali A. Rad ◽  
Geoffrey W. Rodgers ◽  
J. Geoffrey Chase ◽  
Stefano Pampanin ◽  
...  

To improve seismic structural performance, supplemental damping devices can be incorporated to absorb seismic response energy. The viscous fluid damper is a well-known solution. However, while they reduce displacement demand, they can increase overall base shear demand in nonlinear structures as they provide resistive forces in all four quadrants of force-displacement response. In contrast, Direction and Displacement Dependent (D3) viscous fluid dampers offer the opportunity to simultaneously reduce structural displacements and the total base-shear force as they only produce resistive forces in the second and fourth quadrants of a structural hysteresis plot. The research experimentally examines the response of a half-scale, 2-storey moment frame steel structure fitted with a 2-4 configuration D3 viscous fluid damper. The structure is also tested with conventional viscous dampers to establish a baseline response and enable comparison of results. Dynamic experimental tests are used to assesses the base shear, maximum drift and residual deformation under 5 different earthquakes (Northridge, Kobe, Christchurch (CCCC), Christchurch (CHHC), and Bam ground motion). Response metrics including base shear, the maximum structural displacement, and peak structural accelerations are used to quantify performance and to assess the response reductions achieved through the addition of dampers. It is concluded that only the 2-4 device is capable of providing concurrent reductions in all three of these structural response metrics.


2014 ◽  
Vol 2014 ◽  
pp. 1-17 ◽  
Author(s):  
Wenke Tang ◽  
Eric M. Lui

A hybrid recentering energy dissipative device that has both recentering and energy dissipation capabilities is proposed and studied in this paper. The proposed hybrid device, referred to as the hybrid shape memory alloy (SMA) recentering viscous fluid (RCVF) energy dissipation device, connects the apex of a chevron brace to an adjoining beam using two sets of SMA wires arranged in series on either side of the brace and a viscous fluid damper arranged in parallel with the SMA wires. The viscous damper is used because being a velocity-dependent device it does not exert any force that counteracts the recentering force from the SMA wires after the vibration of the frame ceases. In the numerical study, the Wilde’s SMA constitutive model is used to model the SMA wires, and the Maxwell model is used to simulate the viscous fluid damper. To demonstrate the viability and effectiveness of the proposed hybrid device, comparative studies are performed on several single-story shear frames and a series of four-story steel frames. The results show that the frames equipped with the hybrid device have noticeably smaller peak top story displacements and residual story drifts when subjected to ground motions at three different intensity levels.


Author(s):  
Fushui Liu ◽  
Zhongjie Shi ◽  
Yang Hua ◽  
Ning Kang ◽  
Yikai Li ◽  
...  

Since the intake valve close timing (IVC) directly determines the amount of displacement backflow and the amount of fresh charge trapped in the cylinder, optimizing the IVC is important to improve the performance of the diesel engine. In this paper, the relationship between the IVC and the displacement backflow of the cylinder at the high-speed condition was studied by establishing a one-dimensional (1D) gas dynamic model of a single-cylinder diesel engine. The results show that the forward airflow mass of intake and the backflow increase as the IVC retards, and the airflow mass trapped in cylinder increases at first and then decreases. It is interesting to find that the backflow does not equal zero when the air mass trapped in cylinder is the largest, which is different from the traditional optimizing strategy on the IVC. That is to say, there exists a misalignment between the maximum-volume-efficiency IVC and the none-backflow IVC. To further verify this interesting misalignment, the airflow characteristics at the optimized IVC condition are studied by establishing a three-dimensional (3D) simulation. It is found that the appearance of backflow is a gradual process, and there exists an overall backflow when the engine volume efficiency reaches its maximum value. In addition, the misalignment is reduced as the mean valve-closing velocity increases. The misalignment equals to 0 only if the mean valve-closing velocity approaches infinity.


2012 ◽  
Vol 562-564 ◽  
pp. 1079-1082
Author(s):  
Yong Feng Liu ◽  
Pu Cheng Pei ◽  
Jian Wei Yang ◽  
Ai Hua Zhu

In order to establish the three-dimensional model of the crankshaft piston group, the application of characteristic modeling method was proposed directly through the designer to extract features from the BULL operations, and finally form a part model of the design and definition. Analysis of the expression of the crankshaft features and characteristics of the link, use Pro-E to build a diesel engine crankshaft and the piston rod group of feature modeling. a new three-dimensional assembly drawings was built. It provide a new design ideas for reserachers.


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