Sartre - Safe Road Trains for the Environment Reducing Fuel Consumption through Lower Aerodynamic Drag Coefficient

A moving model test method has been proposed to measure the aerodynamic drag coefficient of a high-speed train based on machine vision technology. The total resistance can be expressed as the track friction resistance and the aerodynamic drag according to Davis equation. Cameras are set on one side of the track to capture the pictures of the train, from which the line marks on the side surface of the train are extracted and analyzed to calculate the speed and acceleration of the train. According to Newton’s second law, the aerodynamic drag coefficient can be resolved through multiple tests at different train speeds. Comparisons are carried out with the full-scale coasting test, wind tunnel test, and numerical simulation; good agreement is obtained between the moving model test and the full-scale field coasting test with difference within 1.51%, which verifies that the method proposed in this paper is feasible and reliable. This method can accurately simulate the relative movement between the train, air, and ground. The non-contact measurement characteristic will increase the test accuracy, providing a new experimental method for the aerodynamic measurement.

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Numerical Study of the Generic Sports Utility Vehicle Design with a Drag Reduction Add-On Device

Journal of Computational Engineering ◽

10.1155/2014/785294 ◽

2014 ◽

Vol 2014 ◽

pp. 1-17 ◽

Cited By ~ 1

Author(s):

Shubham Singh ◽

M. Zunaid ◽

Naushad Ahmad Ansari ◽

Shikha Bahirani ◽

Sumit Dhall ◽

...

Keyword(s):

Drag Reduction ◽

Drag Coefficient ◽

Aerodynamic Drag ◽

Numerical Study ◽

Fuel Efficiency ◽

Ansys Fluent ◽

Mean Pressure ◽

Aerodynamic Drag Coefficient ◽

Total Base ◽

Aerodynamic Parameters

CFD simulations using ANSYS FLUENT 6.3.26 have been performed on a generic SUV design and the settings are validated using the experimental results investigated by Khalighi. Moreover, an add-on inspired by the concept presented by Englar at GTRI for drag reduction has been designed and added to the generic SUV design. CFD results of add-on model and the basic SUV model have been compared for a number of aerodynamic parameters. Also drag coefficient, drag force, mean surface pressure, mean velocities, and Cp values at different locations in the wake have been compared for both models. The main objective of the study is to present a new add-on device which may be used on SUVs for increasing the fuel efficiency of the vehicle. Mean pressure results show an increase in the total base pressure on the SUV after using the device. An overall reduction of 8% in the aerodynamic drag coefficient on the add-on SUV has been investigated analytically in this study.

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Aerodynamic drag coefficient over equatorial coastal industrialized and urban areas

Journal of Wind Engineering and Industrial Aerodynamics ◽

10.1016/j.jweia.2012.07.006 ◽

2012 ◽

Vol 110 ◽

pp. 25-39 ◽

Cited By ~ 3

Author(s):

Yusri Yusup

Keyword(s):

Drag Coefficient ◽

Urban Areas ◽

Aerodynamic Drag ◽

Aerodynamic Drag Coefficient

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Method to Reduce Drag Coefficient for Fuel Efficiency in Semi-Truck Trailer and Trailer Stability

Volume 7: Fluids Engineering ◽

10.1115/imece2018-86584 ◽

2018 ◽

Author(s):

Anu R. Nair ◽

Fred Barez ◽

Ernie Thurlow ◽

Metin Ozen

Keyword(s):

Drag Coefficient ◽

Fuel Consumption ◽

Aerodynamic Drag ◽

Fuel Efficiency ◽

Rolling Resistance ◽

Ansys Fluent ◽

Improve Fuel Efficiency ◽

Area Of Interest ◽

Streamlined Body ◽

External Forces

Heavy commercial vehicles due to their un-streamlined body shapes are aerodynamically inefficient due to higher fuel consumption as compared to passenger vehicles. The rising demand and use of fossil fuel escalate the amount of carbon dioxide emitted to the environment, thus more efficient tractor-trailer design becomes necessary to be developed. Fuel consumption can be reduced by either improving the driveline losses or by reducing the external forces acting on the truck. These external forces include rolling resistance and aerodynamic drag. When driving at most of the fuel is used to overcome the drag force, thus aerodynamic drag proves an area of interest to study to develop an efficient tractor-trailer design. Tractor-trailers are equipped with standard add-on components such as roof defectors, boat tails and side skirts. Modification of these components helps reduce drag coefficient and improve fuel efficiency. The objective of this study is to determine the most effective geometry of trailer add-on devices in semi-truck trailer design to reduce the drag coefficient to improve fuel efficiency and vehicle stability. The methodology consisted of CFD analysis on Mercedes Benz Actros using ANSYS FLUENT. The simulation was performed on the tractor-trailer at a speed of 30m/s. The analysis was performed with various types of add-on devices such as side skirts, boat tail and vortex generators. From the simulation results, it was observed that addition of tractor-trailer add-on devices proved beneficial over modifying trailer geometry. Combination of add-on devices in the trailer underbody, rear and front sections was more beneficial in reducing drag coefficient as compared to their individual application. Improving fuel efficiency by 17.74%. Stability of the tractor-trailer is improved due to the add-on devices creating a streamlined body and reducing the low-pressure region at the rear end of the trailer.

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