A New Computational Model about Vehicle’s Sliding Resistance Coefficients

2011 ◽  
Vol 228-229 ◽  
pp. 60-65
Author(s):  
Hong Liang Lin ◽  
Qiang Yu ◽  
Xue Li Zhang
Keyword(s):  
Drag Coefficient ◽  
Dynamic Performance ◽  
Great Influence ◽  
Rolling Resistance ◽  
Resistance Coefficient ◽  
Calculation Model ◽  
Air Drag ◽  
Sliding Resistance ◽  
Rolling Resistance Coefficient ◽  
Resistance Coefficients

Vehicle’s sliding resistance mainly includes rolling resistance, air drag resistance and friction within the transmission, wheel bearings and other related components. Among those, rolling resistance and air drag always exist whenever vehicle is running, so they have great influence on vehicle’s dynamic performance and fuel economy. Therefore, it is important to determine vehicle’s rolling resistance coefficient and air drag coefficient quickly and accurately in order to operate vehicle properly and reduce the vehicle’s fuel consumption. Combining theoretical analysis with experimental verification, calculation model based on road coasting test was given by means of least squares principle. And through which vehicle rolling resistance coefficient and air drag coefficient were determined easily. Then by using the test data from some Minibus, the vehicle's rolling resistance coefficient and air drag coefficient are calculated according to established model. The computation result shows that rolling resistance coefficient is a linear function of the speed and the air drag coefficient is constant. Finally, the analysis shows that the calculation model is simple, precise and useful.

scholarly journals In Use Determination of Aerodynamic and Rolling Resistances of Heavy-Duty Vehicles

2021 ◽  
Vol 13 (2) ◽  
pp. 974
Author(s):  
Dimitrios Komnos ◽  
Stijn Broekaert ◽  
Theodoros Grigoratos ◽  
Leonidas Ntziachristos ◽  
Georgios Fontaras
Keyword(s):  
Drag Coefficient ◽  
Fuel Consumption ◽  
Carbon Dioxide Emissions ◽  
Rolling Resistance ◽  
Resistance Coefficient ◽  
Heavy Duty ◽  
Air Drag ◽  
Speed Test ◽  
Rolling Resistance Coefficient ◽  
Heavy Duty Vehicles

A vehicle’s air drag coefficient (Cd) and rolling resistance coefficient (RRC) have a significant impact on its fuel consumption. Consequently, these properties are required as input for the certification of the vehicle’s fuel consumption and Carbon Dioxide emissions, regardless of whether the certification is done via simulation or chassis dyno testing. They can be determined through dedicated measurements, such as a drum test for the tire’s rolling resistance coefficient and constant speed test (EU) or coast down test (US) for the body’s air Cd. In this paper, a methodology that allows determining the vehicle’s Cd·A (the product of Cd and frontal area of the vehicle) from on-road tests is presented. The possibility to measure these properties during an on-road test, without the need for a test track, enables third parties to verify the certified vehicle properties in order to preselect vehicle for further regulatory testing. On-road tests were performed with three heavy-duty vehicles, two lorries, and a coach, over different routes. Vehicles were instrumented with wheel torque sensors, wheel speed sensors, a GPS device, and a fuel flow sensor. Cd·A of each vehicle is determined from the test data with the proposed methodology and validated against their certified value. The methodology presents satisfactory repeatability with the error ranging from −21 to 5% and averaging approximately −6.8%. A sensitivity analysis demonstrates the possibility of using the tire energy efficiency label instead of the measured RRC to determine the air drag coefficient. Finally, on-road tests were simulated in the Vehicle Energy Consumption Calculation Tool with the obtained parameters, and the average difference in fuel consumption was found to be 2%.

Determination of the rolling resistance of roller skis

2016 ◽  
Vol 231 (1) ◽  
pp. 50-56
Author(s):  
Kurt Schindelwig ◽  
Martin Mössner ◽  
Michael Hasler ◽  
Werner Nachbauer
Keyword(s):  
Normal Load ◽  
Rolling Resistance ◽  
Resistance Coefficient ◽  
Equal Opportunities ◽  
Cross Country Skiing ◽  
Cross Country ◽  
Rolling Resistance Coefficient ◽  
Moving Patterns ◽  
Resistance Coefficients

The rolling resistance of skis used in roller skiing competitions should resemble the gliding resistance of cross-country skis to allow specific training and moving patterns for cross-country skiing and to guarantee equal opportunities for athletes in roller ski races. Therefore, the purpose of this work was to develop a portable rolling resistance meter to precisely measure the rolling resistance of roller skis. Measurements were based on recordings of the angular deceleration of a flywheel due to the rolling resistance between a roller ski’s wheel and the flywheel’s steel surface. Rolling resistance coefficients of four roller ski types ranged between 0.019 and 0.025. Measurements of the rolling resistance coefficient showed a precision of 1.26%. Substantial rolling resistance coefficient variations (10%) were observed for wheels of the same type. Furthermore, the rolling resistance coefficient was found to be negatively correlated with normal load or ambient temperature. The proposed rolling resistance meter is appropriate to determine the rolling resistance coefficient of roller skis’ wheels precisely.

scholarly journals The determination of the rolling resistance coefficient of a passenger vehicle with the use of selected road tests methods

2019 ◽  
Vol 254 ◽  
pp. 04006 ◽  
Author(s):  
Bartłomiej Pałasz ◽  
Konrad J. Waluś ◽  
Łukasz Warguła
Keyword(s):  
Rolling Resistance ◽  
Resistance Coefficient ◽  
Calculation Model ◽  
Passenger Vehicle ◽  
Calculation Methods ◽  
The Road ◽  
Wide Range ◽  
Rolling Method ◽  
Rolling Resistance Coefficient

Wide range of laboratory and road methods of determining the rolling resistance coefficient impose the need to find an effective way of its estimation. The obtained values of this coefficient differ depending from the assumed calculation model and influence the quality and quantity assessment of cooperation processes between tire and surface. The article presents two experimental methods of determining the rolling resistance coefficient. Road tests were carried out with the use of coast-down and free-rolling method. For each of the road methods the value of the rolling resistance coefficient was determined in three ways. It allowed to compare the selected research methods and calculation methods with the values available in literature.

scholarly journals Limitations of vehicle movement resistances: rolling resistance

2018 ◽  
Vol 19 (12) ◽  
pp. 256-259
Author(s):  
Piotr Wrzecioniarz ◽  
Wojciech Ambroszko ◽  
Aleksandra Pindel
Keyword(s):  
Rolling Resistance ◽  
Resistance Coefficient ◽  
Rolling Resistance Coefficient ◽  
Vehicle Movement

In the paper limitations and exemplary methods of rolling resistance minimization are described. Changes of value of rolling resistance coefficient during years and values for exemplary rolling pairs are presented. Conclusions about future progress are formulated.

scholarly journals Rolling Resistance Estimation for PCR Tyre Design Using the Finite Element Method

2020 ◽  
Author(s):  
Sutisna Nanang Ali
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Rolling Resistance ◽  
Resistance Coefficient ◽  
Total Force ◽  
Exhaust Gas Emission ◽  
Deformation Force ◽  
Rolling Resistance Coefficient ◽  
Alternative Designs ◽  
Element Method

This study presents rolling resistance estimation in the design process of passenger car radial (PCR) tyre by using finite element method. The rolling resistance coefficient of tyres has been becoming one of main requirements within the regulation in many countries as it is related to the level of allowable exhaust gas emission generated by vehicle. Therefore, the tyre being designed must be digitally simulated using finite element method before the tyre is manufactured to provide a high confident level and avoid unnecessary cost related to failure physical product testing. The simulation firstly computes the deformation of several alternative designs of tyres under certain loading, and then the value of deformation force in each tyre component during deformation took place is calculated. The total force of deformation is considered as energy loss or hysteresis loss resulted in tyre rolling resistance. The experiment was carried out on three different tyre designs: two grooves, three grooves, and four grooves. The four groove tyre design gave the smallest rolling resistance coefficient (RRC). Finally, the simulation was continued to compare different crown radius of the tyres and the result shows that the largest crown radius generates the lowest rolling resistance.

scholarly journals Determination of rolling resistance coefficient based on normal tyre stiffness

2018 ◽  
Vol 327 ◽  
pp. 042093
Author(s):  
S P Rykov ◽  
V N Tarasuyk ◽  
V S Koval ◽  
N I Ovchinnikova ◽  
A I Fedotov ◽  
...  
Keyword(s):  
Rolling Resistance ◽  
Resistance Coefficient ◽  
Rolling Resistance Coefficient

scholarly journals DIMENSIONAREA SISTEMULUI DE PROPULSIE AL UNUI VEHICUL ELECTRIC. STUDIU DE CAZ

2021 ◽  
Vol 2020 (1) ◽  
pp. 1-14
Author(s):  
Alexandru TURCANU ◽  
Leonard-Călin-Valentin DOBRE
Keyword(s):  
Traction Force ◽  
Rolling Resistance ◽  
Resistance Coefficient ◽  
Gear Ratio ◽  
Calculation Model ◽  
The Road ◽  
Electric Car ◽  
Resistive Forces ◽  
Wheel Radius ◽  
Resistance Forces

This paper aims to present to readers concrete mathematical models, transposed into simulation schemes, to calculate the forces acting on a car at its interaction with the road and the atmosphere, to properly size the electric motor and batteries of an electric car. For the calculation of these forces, a table with predefined values ​​such as vehicle mass, rolling resistance coefficient, gear ratio, wheel radius, was used throughout the work. In the second section of the paper, the values ​​of the resistance forces that oppose the movement of the vehicle and the traction force necessary to overcome these resistive forces were determined. The mathematical calculation model was compiled in Matlab and the graphs in figures 3-9 were obtained.

scholarly journals The determination of the rolling resistance coefficient of a passenger vehicle with the use of roller test bench method

2019 ◽  
Vol 254 ◽  
pp. 04007 ◽  
Author(s):  
Bartłomiej Pałasz ◽  
Konrad J. Waluś ◽  
Łukasz Warguła
Keyword(s):  
Energy Consumption ◽  
Experimental Research ◽  
Research Method ◽  
Test Bench ◽  
Rolling Resistance ◽  
Resistance Coefficient ◽  
Laboratory Method ◽  
Passenger Vehicle ◽  
Rolling Resistance Coefficient

Contemporary vehicle are designer to be eco-friendly. One of the factors limiting the energy consumption of driving processes is a low value of the rolling resistance coefficient. The rolling resistance depends on the construction features of a tire, exploitation conditions and the type of surface the car moves on. This article presents the results of experimental research of determining the rolling resistance coefficient with the use of laboratory method of roller test bench. The results presented here are a part of a wider research of determining the rolling resistance coefficient and the influence of research method on its value.

Method of estimating the rolling resistance coefficient of vehicle tyre using the roller dynamometer

2020 ◽  
Vol 234 (13) ◽  
pp. 3194-3204
Author(s):  
Adrian Soica ◽  
Adrian Budala ◽  
Vlad Monescu ◽  
Slawomir Sommer ◽  
Wojciech Owczarzak
Keyword(s):  
Rolling Resistance ◽  
Resistance Coefficient ◽  
Test Method ◽  
Test Facility ◽  
Vehicle Speed ◽  
Chassis Dynamometer ◽  
The Past ◽  
Test Conditions ◽  
Resistance Coefficients ◽  
Roll Out

The tendency in the past few years has been to introduce tyres with lower rolling resistance coefficients to the market. This paper presents a mathematical method for determining the rolling resistance coefficients variation depending on the speed. The method uses power balance which results from automobile dynamics while rolling on chassis dynamometer. The rolling resistance coefficients of tyres obtained through ‘drum test method’, for which the rolling resistance coefficients variation is known in terms of vehicle speed, are considered as reference values, while than rolling resistance coefficients of tyres obtained through ‘MAHA roller dynamometer’ using the recorded lost drag power in the roll-out phase on the stand are considered as tested values. The rolling resistance coefficients variation could be determined up to the maximum permissible speed of the tyre, for all wheels trained on the stand and not just for one tyre, as determined in laboratory conditions. The test conditions are similar to those in real road conditions, where the temperature of the environment and wheels cannot be controlled. The values obtained by the authors’ proposed method were compared with the values obtained by the ‘drum test method’. The main contribution of the proposed method is to estimate the rolling resistance coefficients without using a very expensive test facility.

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