Drag factor calculation per wheel in a motorcycle

2021 ◽  
Author(s):  
Brunori Nicolás
Keyword(s):  
Drag Factor

Drag Factors From Rollover Crash Testing for Crash Reconstructions

2011 ◽  
Author(s):  
Mark W. Arndt ◽  
Stephen M. Arndt ◽  
Donald Stevens
Keyword(s):  
Standard Deviation ◽  
Crash Testing ◽  
Naturally Occurring ◽  
Analysis Technique ◽  
Global Positioning ◽  
Original Works ◽  
Rollover Crash ◽  
Crash Tests ◽  
Gps Antenna ◽  
Drag Factor

A study of numerous published rollover tests was conducted by reexamination of the original works, analysis of their data, and centralized compilation of their results. Instances were identified where the original reported results for trip speed were in error, requiring revision because the analysis technique employed extrapolation versus integration and lacked correction for offset errors that develop by placing the Global Positioning System (GPS) antenna away from the vehicle Center of Gravity (CG). An analysis was performed demonstrating revised results. In total, 81 dolly rollover crash tests, 24 naturally occurring rollover crash tests, and 102 reconstructed rollovers were identified. Of the 24 naturally occurring tests, 18 were steer-induced rollover tests. Distributions of the rollover drag factors are presented. The range of drag factors for all examined dolly rollovers was 0.38 g to 0.50 g with the upper and lower 15 percent statistically trimmed. The average drag factor for dolly rollovers was 0.44 g (standard deviation = 0.064) with a reported minimum of 0.31 g and a reported maximum of 0.61 g. After revisions, the range of drag factors for the set of naturally occurring rollovers was 0.39 g to 0.50 g with the upper and lower 15 percent statistically trimmed. The average drag factor for naturally occurring rollovers was 0.44 g (standard deviation = 0.063) with a reported minimum of 0.33 g and a reported maximum of 0.57 g. These results provide a more probable range of the drag factor for use in accident reconstruction compared to the often repeated assertion that rollover drag factors range between 0.4 g and 0.65 g.

scholarly journals An Overview of Heavy Trucks/Buses Braking Performance

1991 ◽  
Vol 8 (1) ◽  
Author(s):  
Richard M. Ziernicki
Keyword(s):  
Statistical Data ◽  
Vehicle Speed ◽  
Test Results ◽  
Heavy Duty ◽  
Braking Performance ◽  
Emergency Braking ◽  
Heavy Trucks ◽  
Brake Performance ◽  
Drag Factor ◽  
Heavy Duty Vehicles

The writer discusses the performance of heavy duty vehicles during emergency braking. The paper reviews statistical data related to the trucking accidents, and discusses brake performance, tires, and the stopping ability of heavy duty vehicles. Relationships between drag factor, coefficient of friction, vehicle speed, type of tire, road surface, brake design, and brake temperature are discussed. Some of the test results performed on heavy trucks are presented. The discussion is general in order to make the presentation useful both to practicing reconstruction specialists, and to attorneys.

Some Remarks on Vortex Drag and its Spanwise Distribution in Incompressible Flow

1968 ◽  
Vol 72 (691) ◽  
pp. 623-625 ◽  
Author(s):  
H. C. Garner
Keyword(s):  
Theoretical Data ◽  
Leading Edge ◽  
List Type ◽  
Surface Theory ◽  
Lifting Surface ◽  
Line Theory ◽  
Lifting Line ◽  
Swept Wings ◽  
Lifting Line Theory ◽  
Drag Factor

Summary Theoretical data from lifting-surface theory are presented to illustrate (i) that the vortex drag factor is closely related to the half-wing spanwise centre of pressure on simple planforms without camber or twist, (ii) that lifting-line theory is useless for predicting the spanwise distribution of vortex drag on swept wings, (iii) that recent numerical improvements in lifting-surface theory help to reconcile the concepts of wake energy and leading-edge suction in relation to vortex drag.

An experimentally quantifiable solute drag factor

2008 ◽  
Vol 56 (6) ◽  
pp. 1374-1379 ◽  
Author(s):  
S DILLON
Keyword(s):  
Solute Drag ◽  
Drag Factor

scholarly journals Drag Characteristics of Competitive Swimming Children and Adults

2008 ◽  
Vol 24 (1) ◽  
pp. 35-42 ◽  
Author(s):  
Per-Ludvik Kjendlie ◽  
Robert Keig Stallman
Keyword(s):  
Perturbation Method ◽  
Froude Number ◽  
Wave Drag ◽  
Maximal Velocity ◽  
Evaluation Tool ◽  
Competitive Swimming ◽  
Velocity Decay ◽  
Competitive Swimmers ◽  
Drag Factor ◽  
Swimming Technique

The aims of this study were to compare drag in swimming children and adults, quantify technique using the technique drag index (TDI), and use the Froude number (Fr) to study whether children or adults reach hull speed at maximal velocity (vmax). Active and passive drag was measured by the perturbation method and a velocity decay method, respectively, including 9 children aged 11.7 ± 0.8 and 13 adults aged 21.4 ± 3.7. The children had significantly lower active (kAD) and passive drag factor (kPD) compared with the adults. TDI (kAD/kPD) could not detect any differences in swimming technique between the two groups, owing to the adults swimming maximally at a higher Fr, increasing the wave drag component, and masking the effect of better technique. The children were found not to reach hull speed atvmax, and their Fr were 0.37 ± 0.01 vs. the adults 0.42 ± 0.01, indicating adults’ larger wave-making component of resistance atvmaxcompared with children. Fr is proposed as an evaluation tool for competitive swimmers.

The Drag Due to Lift of Plane Wings at Subsonic Speeds

1966 ◽  
Vol 70 (665) ◽  
pp. 595-599 ◽  
Author(s):  
D. Gardner ◽  
J. Weir
Keyword(s):  
Wind Tunnel ◽  
Reynolds Numbers ◽  
Considerable Improvement ◽  
Induced Drag ◽  
Wind Tunnel Measurements ◽  
Lift Curve ◽  
Mach Numbers ◽  
Drag Factor

SummaryThis note outlines a method for the prediction of drag due to lift of plane wings at Mach numbers below drag divergence and Reynolds numbers above 106. The method is based on the correlation of a number of wind tunnel measurements in terms of the effect of viscosity on lift curve slope. A comparison is made of the accuracy of estimating the induced drag factor, k, using this method, with the method of ret. 1, and it is shown that considerable improvement has been made, and that, in general, the predicted value of k is within 10% of experiment.

scholarly journals KAJIAN NILAI KOEFISIEN HAMBAT PADA SALURAN TERBUKA

2017 ◽  
Author(s):  
cahya sujatmiko
Keyword(s):  
Drag Coefficient ◽  
Channel Flow ◽  
Open Channel ◽  
Open Channel Flow ◽  
Flow Equation ◽  
Scale Model ◽  
Natural Phenomenon ◽  
Back Door ◽  
Drag Factor ◽  
Bar Diameter

Open channel flow is the natural phenomenon that research by hydraulic engineer. Roughness of thechannel is the drag factor of the flow and the value depend on the roughness caracteristics. Chezy coefficient is the coefficient of flow equation determining velocity at the channel. The value of the chezy coefficient is depend of flow caracteristics and roughness of the channel. Research target conducted to learn the value of the chezy coefficient and drag coefficient at the open channel flow with the cylindrical roughness and determine the parameter having an effect on and also relation usher the parameter. The result of cylindrical will be application to the flow with the resistance grow on mangrove. This research used 6 vertical bar model by 6 variation of density to 2 vertical bar diameter. Simulation model the vertical bar conducted by 4 variation of discharge the stream range from 0,00825 until 0,01374 m3/s and 5 variation of stream deepness by turning around back door ( tail gate). Scale model 1 : 10 used to support the measurement correctness beside consideration of equipments limitation. Research data analysis use the way of comparison between theoretical with the research to yield the relation of non dimensionaless. Result of this research indicate that ever greater of density, depth flow and diameter of cylindrical hence yielded chezy coefficient smaller that mean drag flow is greater. Chezy coefficient yielded range 3,82 – 10,579 m1/2/s with the density range 0,498 – 6,883 while drag coefficient value result of average 0,95. Average velocity for cylindrical roughness can be determine with the equation of Chezy

A Study of Hydrodynamic Characteristics of Boundary Layer With Algae Roughness

2004 ◽  
Vol 41 (02) ◽  
pp. 60-66
Author(s):  
Chelakara S. Subramanian ◽  
Nagahiko Shinjo ◽  
Sathya N. Gangadharan
Keyword(s):  
Boundary Layer ◽  
Pressure Gradient ◽  
Free Stream ◽  
Order Term ◽  
Viscous Drag ◽  
Laser Doppler Velocimeter ◽  
Hydrodynamic Characteristics ◽  
Smooth Wall ◽  
Log Law ◽  
Drag Factor

Filamentous algae fouling, such as Enteromorpha clathrata, is a soft and hairylike roughness that sometimes grows even thicker than a normal boundary layer. Typically, such fouling has been treated as traditional roughness functions to yield hydrodynamic characteristics. This technique has been successfully used for a thin fouling layer. However, it may not be applicable on a thicker layer, as the present study found substantial fluid flow within the layer. For such cases, the roughness cannot be treated simply as a passive geometric variable, but its kinematics and interactions with the flow must be considered. The inner law (log law) dynamics may be abnormal to yield any meaningful roughness function if it is calculated in the traditional way as the departure of a rough-wall log law profile over a smooth-wall log law profile. In the present research, velocity measurement of the E. clathrata roughness boundary layer using pitot-static tube and laser Doppler velocimeter (LDV) were compared. Large discrepancies in the velocity profiles within and in the vicinity of the roughness layer were observed between the two methods. The pitot-static tube data showed significantly high velocities (60% to 80% of the free stream) in the inner layer as compared to a smooth wall boundary layer. This local increase in velocity is believed to be the result of elastic transfer of free-stream energy to the near-wall motions by the E. clathrata filaments. Consequently, the usual assumption of the normal pressure gradient as a negligible second-order term for a normal zero-pressure gradient boundary layer may not be valid for the present kind of roughness. The LDV velocity measurements near and within the roughness layer have large uncertainties due to interference of the probe volume by the E. clathrata filaments. Above the roughness, the pitot-static tube and LDV profiles show relatively good agreement. It is concluded that for accurate prediction of the wall shear stress with E. clathrata-type of bio-fouling roughness, the Clauser velocity loss function should include a form drag factor instead of only the viscous drag factor.

scholarly journals Relation between Maximal Anaerobic Power Output and Tests on Rowing Ergometer

2017 ◽  
Vol 57 (1) ◽  
pp. 68-75a ◽  
Author(s):  
Matej Šmída ◽  
Michal Clementis ◽  
Dušan Hamar ◽  
Yvetta Macejková
Keyword(s):  
Power Output ◽  
Anaerobic Power ◽  
Average Power ◽  
A Value ◽  
Rowing Performance ◽  
Rowing Ergometer ◽  
Anaerobic Power Output ◽  
Maximal Anaerobic Power ◽  
Drag Factor ◽  
Factor Set

SummaryAim of this study was to compare relation between maximal anaerobic power output and 2,000 m test on rowing ergometer and relation between 6,000 m test and 2,000 m on rowing ergometer. It can be assumed that 2,000 m performance on rowing ergometer will significantly correlate with maximal anaerobic power output and 6,000 m performance. A group of 9 welltrained rowers (age: 18.3 years ± 2.8 years, sport age: 4.9 years ± 3.7 years, weight: 78.9 kg ± 12.2 kg, height: 182.3 cm ± 7.6 cm) performed three tests in 1 week to determine maximal anaerobic power, 6,000 m and 2,000 m performance on Concept 2 model D rowing ergometer. A value of simple maximal stroke out of 10-second all-out test with drag factor set to 200 was taken as a measure of maximal anaerobic power. Drag factor for 6,000 m and 2,000 m test was set individually. Average power during these tests was record. Research showed that both maximal anaerobic power and 6,000 m test correlated with 2,000 m test on rowing ergometer significantly (rmap= 0.93 p < 0.01, r6k= 0.95 p < 0.01). Maximal anaerobic power and 6,000 m tests seem to be good predictors for 2,000 m score on rowing ergometer. However, maximal anaerobic power test can be used to monitor rowing performance during specific training cycle instead of longer and more demanding 6,000 m test.

Sign in / Sign up

Export Citation Format

Share Document