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61.
Performance estimation model of a torque converter part I: Correlation between the internal flow field and energy loss coefficient 总被引:3,自引:0,他引:3
B. S. Kim S. B. Ha W. S. Lim S. W. Cha 《International Journal of Automotive Technology》2008,9(2):141-148
The objective of this paper is to improve the performance estimation model of the internal flow field of a torque converter.
Compared with performance experiment results, the converter based on the one-dimensional model does not satisfy the performance
requirements demanded in practice. Therefore, we need to develop more predictable and reliable performance estimation models.
In order to obtain shape information on three-dimensional blade geometry, a process of reverse engineering conducts a torque
converter assembly, impeller, turbine and stator. In addition, a CFD simulation including mesh generation and post-processing
was carried out to extract equivalent parameters from the internal flow field. The internal flow field can be explained by
analyze the correlation between a performance estimation model and CFD analysis. The equivalent performance model adopts the
variation of energy loss coefficients for a given operating condition according to the application of a changing energy loss
coefficient by the least mean squares method. The estimated equivalent model improves the agreement in performance between
experiments and the theoretical model. This model can reduce the error to within about 3 percent. Furthermore, this procedure
for predicted performance achieves eminence in the estimation of the capacity factor. 相似文献
62.
This paper establishes the simulation model of a city bus on the basis of the EQ6110 bus prototype and its experimental data.
According to the actual urban driving cycle, the fuel economy and the traction performance of the EQ6110 city bus have been
simulated, and factors such as the driving cycle, the loss of power to engine accessories, the gear-shifting strategy, the
fuel shut-off strategy of the engine, etc., which influence on the bus’s fuel economy, are also quantitatively analyzed. Some
conclusions are drawn as follows: (1) driving cycles have a great influence on the fuel economy of a city bus; (2) under the
typical urban driving cycle of the public bus in China, the engine fuel shut-off strategy can save about 1 to 1.5 percent
of the fuel consumption; and (3) the optimized gear-shifting rules can save 6.7 percent of the fuel consumption. Experimental
results verify that the fuel economy for the EQ6110 public bus is improved by 7.2 pecent over the actual Wuhan urban driving
cycle of the current public bus in China. 相似文献
63.
This paper presents a steering control method for lane-following in a vehicle using an image sensor. With each image frame
acquired from the sensor, the steering control method determines target position and direction, and constructs a travel path
from the current position to the target position either as an Arc-path or S-path. The steering angle is calculated from the
travel path thus generated, and the vehicle follows the travel path via motor-control. The method was tested using a vehicle
dubbed as KAV (Korea Autonomous Vehicle) along an expressway (Seoul Inner Beltway) trajectory with a variety of radii (50
m ∼ 300 m) while traveling at a speed of 60 km/h to 80 km/h. Compared with an experienced human driver, the method showed
little much difference in performance in terms of lane-center deviation. The proposed method is currently employed for high
speed autonomous driving as well as for stop and go traffic. 相似文献
64.
B. Blanco A. Alonso L. Kari N. Gil-Negrete J. G. Giménez 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2018,56(4):529-552
The finite length nature of rail-pad supports is characterised by a Timoshenko beam element formulation over an elastic foundation, giving rise to the distributed support element. The new element is integrated into a vertical track model, which is solved in frequency and time domain. The developed formulation is obtained by solving the governing equations of a Timoshenko beam for this particular case. The interaction between sleeper and rail via the elastic connection is considered in an analytical, compact and efficient way. The modelling technique results in realistic amplitudes of the ‘pinned–pinned’ vibration mode and, additionally, it leads to a smooth evolution of the contact force temporal response and to reduced amplitudes of the rail vertical oscillation, as compared to the results from concentrated support models. Simulations are performed for both parametric and sinusoidal roughness excitation. The model of support proposed here is compared with a previous finite length model developed by other authors, coming to the conclusion that the proposed model gives accurate results at a reduced computational cost. 相似文献
65.
66.
A.Д.KOHЮXOB 《铁道机车车辆工人》2002,(5):22-26
1 货车质量 俄罗斯运用敞车的载重量为68~70 t,车辆自重为22 t,轴重为22.5 t,车辆毛重为90 t,载重量与车辆自重比为3.09~3.18.而美国批量生产的敞车载重量为106~110 t,自重为19~20 t,轴重为32.5 t,车辆毛重130 t,载重量与自重之比为5.5~5.65(表1). 相似文献
67.
68.
A. G. Thompson B. R. Davis 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2003,39(3):245-253
Summary Matrix expressions are developed for the direct computation of rms values for the optimal control forces, front and rear suspension strokes and dynamic tyre deflections in a half-car model on a random road of given roughness. A quadratic performance index is employed with assumed weighting factors and evaluated in the same computation. 相似文献
69.
从上世纪90年代早期到目前为止,尼日利亚联邦政府并没对航运业和造船修理业投入太多精力。一个典型例子就是,由于对这些行业不够重视导致了前尼日利亚国家货运公司(NNSL)的衰败及倒闭。1996年,尼日利亚联合货运公司(NUL)成立。但新公司的成立并 相似文献
70.