Numerical Simulation to Investigate Influence of Additional Devices on Aerodynamic Drag for Heavy-Duty Commercial Truck

2012 ◽  
Vol 209-211 ◽  
pp. 2089-2093 ◽  
Author(s):  
Xin Yu Wang ◽  
Xing Jun Hu ◽  
Lei Liao ◽  
Teng Fei Li
Keyword(s):  
Numerical Simulation ◽  
Drag Coefficient ◽  
Emission Reduction ◽  
Aerodynamic Drag ◽  
Great Influence ◽  
Aerodynamic Characteristics ◽  
Heavy Duty ◽  
Aerodynamic Drag Coefficient ◽  
Made In China ◽  
Made In

To reduce the aerodynamic drag coefficient of a heavy-duty commercial truck made in China, the aerodynamic characteristics of models with additional devices are researched by adopting numerical simulation and taking a certain made-in-china truck model as research object. The mechanism and the effect of reduction of drag coefficient are analyzed and the optimization of model is gained based on contrast to the drag coefficient of base model. The results indicate that the drag coefficient descends in the most degree after roof fairing of cab is applied and the shape of roof fairing has a great influence on drag. The grille and separator can reduce drag coefficient. The research results can reduce the drag coefficients and provide the theoretical references for energy conservation and emission reduction of heavy-duty trucks

Influence of Engine Cabin Simplification on Aerodynamic Characteristics of Car

2014 ◽  
Vol 1042 ◽  
pp. 188-193 ◽  
Author(s):  
Xing Jun Hu ◽  
Jing Chang
Keyword(s):  
Numerical Simulation ◽  
Aerodynamic Drag ◽  
Aerodynamic Characteristics ◽  
Thin Plates ◽  
Average Thickness ◽  
Two Dimensional ◽  
Engine Cooling ◽  
Aerodynamic Drag Coefficient ◽  
Simulation Results ◽  
The Impact

In order to analyze the impact of engine cabin parts on aerodynamic characteristics, the related parts are divided into three categories except the engine cooling components: front thin plates (average thickness of 2mm), bottom-suspension and interior panels. The aerodynamic drag coefficient (Cd) were obtained upon the combination schemes consisting of the three types of parts by numerical simulation. Results show that Cd by simulation is closer to the test value gained by the wind tunnel experiment when front thin plates were simplified to the two-dimensional interface with zero thickness. The error is only 5.23%. Meanwhile this scheme reduces grid numbers, thus decreasing the calculating time. As the front thin plates can guide the flow, there is no difference on the Cd values gained from the model with or without bottom-suspension or interior panels when the engine cabin contains the front thin plates; while only both bottom-suspension and interior panels are removed, the Cd value can be reduced when the cabin doesn’t contain the front thin plates.

Numerical Simulation on Aerodynamic Characteristics of Heavy-Duty Commercial Vehicle

2011 ◽  
Vol 346 ◽  
pp. 477-482 ◽  
Author(s):  
Zhe Zhang ◽  
Ying Chao Zhang ◽  
Jie Li ◽  
Jia Wang
Keyword(s):  
Numerical Simulation ◽  
Fuel Economy ◽  
High Speed ◽  
Aerodynamic Drag ◽  
Aerodynamic Characteristics ◽  
National Standards ◽  
Heavy Duty ◽  
Commercial Vehicles ◽  
Automotive Technology ◽  
New Research

With the development of automotive technology and high-speed highway construction, the speed of the vehicles increase which cause the significant increase in the aerodynamic drag when road vehicles are moving. Thereby the power of the vehicles, fuel economy, operational stability and other properties are affected very seriously. Heavy-duty commercial vehicles as the most efficient way to transport goods on the highway are widely used, and the speed of the vehicles increases faster. Especially the demands for heavy-duty commercial vehicles are increasing in recent years. Reducing the aerodynamic drag by the analysis of external aerodynamic characteristics, improving the fuel economy and reducing energy consumption have become new research topics of heavy-duty commercial vehicles. To make the heavy-duty commercial vehicles meet the national standards of energy saving, a simplified heavy-duty commercial truck model was built in this paper. The numerical simulation of the vehicle was completed based on the theory of the aerodynamics. The aerodynamic characteristics were analyzed, according to the graphs of the pressure distribution, velocity distribution and flow visualization. To improve the aerodynamic characteristics of heavy-duty commercial vehicles, the main drag reduction measures are reducing the vortex of the cab and the container, the end of the container and the bottom of the container.

Investigation of effects of tire contour on aerodynamic characteristics and its optimization

2021 ◽  
pp. 095440702110586
Author(s):  
Lingxin Zhang ◽  
Haichao Zhou ◽  
Guolin Wang ◽  
Huiyun Li ◽  
Qingyang Wang
Keyword(s):  
Aerodynamic Drag ◽  
Great Influence ◽  
Wind Tunnel Test ◽  
Aerodynamic Characteristics ◽  
Design Parameters ◽  
Detached Eddy Simulation ◽  
Eddy Simulation ◽  
Design Variables ◽  
Aerodynamic Drag Coefficient ◽  
Contour Design

Reducing the aerodynamic drag is one of the most important approaches for the development of energy-saving and environment-friendly automobiles. The tire contour has a great influence on the aerodynamic characteristics of automobiles. The aim of this study is to investigate the influence of the tire contour design parameters on the aerodynamic characteristics around a closed wheel, and obtain the optimized tire contour to reduce the automobile aerodynamic drag. A passenger car tire 185/65R14 was selected to conduct the wind tunnel test, and the surface pressure coefficients were used to validate the simulation model established using the detached eddy simulation (DES) model. To decrease tire drag, and taking the upper sidewall height, the tread radii, the tread width, and the transition arc radius of the shoulder as four design variables of contour, a combination of the Latin hypercube experimental design, the Kriging surrogate model, and the adaptive simulated annealing (ASA) algorithm were used to optimize the tire contour design parameters. The changes of flow field around the tire, including the velocity, turbulent kinetic energy, and pressure field were compared and analyzed for further understanding of the drag reduction mechanism. It is found that the aerodynamic drag coefficient of the optimized tire is reduced by 14.5%, and the aerodynamic coefficient drag of the car using the optimized tire is reduced by 7%. The present results are expected to provide useful information for designing new tire structures and improving the aerodynamic performance of the automobile.

scholarly journals Experimental Determination of the Impact of Floats on the Aerodynamic Characteristics of an OSA Model in Symmetric Flow

2021 ◽  
Vol 12 (1) ◽  
pp. 41-58
Author(s):  
Michał FRANT ◽  
Stanisław WRZESIEŃ ◽  
Maciej MAJCHER
Keyword(s):  
Drag Coefficient ◽  
Aerodynamic Drag ◽  
Lift Coefficient ◽  
Aerodynamic Characteristics ◽  
Symmetric Flow ◽  
Aerodynamic Drag Coefficient ◽  
The Impact ◽  
Drag Ratio ◽  
Lift To Drag Ratio

This paper presents the results of experimental determination of the impact of floats on the aerodynamic characteristics of an OSA model in symmetric flow. The studies have been performed in the low-speed wind tunnel at the Military University of Technology (MUT, Warsaw, Poland). The aircraft model was examined at the dynamic pressure q = 500 Pa in the following angle of attack range = -2828. The investigations have been performed for an aircraft model under plain configuration with floats and without floats. The influence of elevator and flap inclination on the aerodynamic characteristics of the model has also been analysed. The obtained values of aerodynamic drag coefficient, lift coefficient, pitching moment coefficient and lift-to-drag ratio have been presented in the form of tables and graphs. The studies performed demonstrated that the use of floats causes the increase of aerodynamic drag coefficient CD, maximum lift coefficient CLmax as well as critical angle of attack cr. The decrease of lift-to-drag ratio has also been observed. Its value in the case of the model with floats was up to 20% lower than in the model without floats. The studies also showed that the model equipped with floats had a lower longitudinal static stability margin than the model without floats.

Effect of Vortex Generators on Aerodynamic Characteristics of a Car

2011 ◽  
Vol 418-420 ◽  
pp. 1873-1877
Author(s):  
Xu Yan ◽  
Jian Ye ◽  
Zhi Ming Zhao ◽  
Xing Jun Hu ◽  
Lei Liao
Keyword(s):  
Drag Reduction ◽  
Drag Coefficient ◽  
Energy Saving ◽  
Emission Reduction ◽  
Aerodynamic Drag ◽  
Vortex Generator ◽  
Aerodynamic Characteristics ◽  
Vortex Generators ◽  
Numerical Stimulation ◽  
Aerodynamic Drag Reduction

In order to reduce the aerodynamic drag, a domestic car was selected as study object to research the size and the layout of the vortex generator with the method numerical stimulation. By comparing the values of drag coefficient (Cd) the cars with vortex generators (VGs) and the original and then analyzing the mechanism of drag reduction, a final optimized strategy was achieved. It was concluded that VGs can lower the Cd of a car but the effect depends on the size and the layout. Our research achievements can serve as reference for automobile aerodynamic drag reduction, and are also significant to energy saving and emission reduction.

Numerical Simulation of Influence of Different Deflectors on Aerodynamic Characteristics of the Heavy Duty Truck

2013 ◽  
Vol 365-366 ◽  
pp. 474-477
Author(s):  
Yu Kun Liu ◽  
Qi Fei Li ◽  
Guan Qun Li ◽  
Ao Liu ◽  
Xing Jun Hu
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Drag Reduction ◽  
Aerodynamic Drag ◽  
Optimal Solution ◽  
Aerodynamic Characteristics ◽  
Heavy Duty ◽  
Heavy Duty Truck

In order to reduce the aerodynamic drag of heavy-duty truck, four different shape and style of deflectors based on the original one are added. With the method of numerical simulation, the influence of deflector on the flow field of the cab and the vehicle was analyzed, and the mechanism of aerodynamic drag and the measures of drag reduction were discussed in the study. When driving at speed of 30m/s, the aerodynamic drag will be significantly reduced with the contributions of all the four deflectors. The optimal solution can reach a reduction about 14%.

Design and Aerodynamic Assessment of Diffuser with Longitudinal Separators for Underbody of Sedan

2012 ◽  
Vol 215-216 ◽  
pp. 1033-1037 ◽  
Author(s):  
Xing Jun Hu ◽  
Rui Zhang ◽  
Jian Ye ◽  
Xu Yan ◽  
Zhi Ming Zhao
Keyword(s):  
Relative Position ◽  
High Speed ◽  
Aerodynamic Drag ◽  
Lift Coefficient ◽  
Great Influence ◽  
Aerodynamic Characteristics ◽  
Aerodynamic Coefficient ◽  
Aerodynamic Drag Coefficient ◽  
Diffuser Angle ◽  
High Speed Vehicle

The aerodynamic characteristics have a great influence on the steering stability and the fuel economics of a high speed vehicle. The diffuser located at the aft part of a car underbody is one of the most important aerodynamic add-on devices. The parameters of the diffuser, including the diffuser angle, the number and the relative position of longitudinal separator (LS), the shape of the end plate and etc, will affect the underbody flow and the wake. Here, diffuser with longitudinal separator of different number and relative position was investigated. Numerical simulation was used to study the aerodynamic characteristics of a simplified sedan with different diffuser of longitudinal separator. The study found aerodynamic coefficient of the car changes little when we change the relative position of diffuser's longitudinal separator. Besides, we also found that increasing the number of the diffuser's longitudinal separator will increase the vehicle's aerodynamic drag coefficient and reduce the vehicle's lift coefficient.

scholarly journals Bearing friction effect on cup anemometer performance modelling

2021 ◽  
Vol 2090 (1) ◽  
pp. 012101
Author(s):  
D Alfonso-Corcuera ◽  
S. Pindado ◽  
M Ogueta-Gutiérrez ◽  
A Sanz-Andrés
Keyword(s):  
Rotation Rate ◽  
Aerodynamic Drag ◽  
Aerodynamic Characteristics ◽  
Friction Torque ◽  
Performance Modelling ◽  
Friction Forces ◽  
Aerodynamic Drag Coefficient ◽  
Yaw Angle ◽  
Cup Anemometer ◽  
Bearing Friction

Abstract In the present work, the effect of the friction forces at bearings on cup anemometer performance is studied. The study is based on the classical analytical approach to cup anemometer performance (2-cup model), used in the analysis by Schrenk (1929) and Wyngaard (1981). The friction torque dependence on temperature was modelled using exponential functions fitted to the experimental results from RISØ report #1348 by Pedersen (2003). Results indicate a logical poorer performance (in terms of a lower rotation speed at the same wind velocity), with an increase of the friction. However, this decrease of the performance is affected by the aerodynamic characteristics of the cups. More precisely, results indicate that the effect of the friction is modified depending on the ratio between the maximum value of the aerodynamic drag coefficient (at 0° yaw angle) and the minimum one (at 180° yaw angle). This reveals as a possible way to increase the efficiency of the cup anemometer rotors. Besides, if the friction torque is included in the equations, a noticeable deviation of the rotation rate (0.5-1% with regard to the expected rotation rate without considering friction) is found for low temperatures.

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