scholarly journals Aerodynamic integration produces a vehicle shape with a negative drag coefficient

2021 ◽  
Vol 118 (27) ◽  
pp. e2106406118
Author(s):  
Kambiz Salari ◽  
Jason M. Ortega
Keyword(s):  
Aerodynamic Drag ◽  
The United States ◽  
Body Axis ◽  
Heavy Vehicle ◽  
Heavy Vehicles ◽  
Drag Coefficients ◽  
The Road ◽  
On The Road ◽  
Vehicle Shape ◽  
Dynamics Simulations

Negative drag coefficients are normally associated with a vessel outfitted with a sail to extract energy from the wind and propel the vehicle forward. Therefore, the notion of a heavy vehicle, that is, a semi truck, that generates negative aerodynamic drag without a sail or any external appendages may seem implausible, especially given the fact that these vehicles have some of the largest drag coefficients on the road today. However, using both wind tunnel measurements and computational fluid dynamics simulations, we demonstrate aerodynamically integrated vehicle shapes that generate negative body-axis drag in a crosswind as a result of large negative frontal pressures that effectively “pull” the vehicle forward against the wind, much like a sailboat. While negative body-axis drag exists only for wind yaw angles above a certain analytical threshold, the negative frontal pressures exist at smaller yaw angles and subsequently produce body-axis drag coefficients that are significantly less than those of modern heavy vehicles. The application of this aerodynamic phenomenon to the heavy vehicle industry would produce sizable reductions in petroleum use throughout the United States.

scholarly journals Comparative Analysis of Effects of Heavy Vehicles on Roads in Southern and Northern Nigeria

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
C. C. Osadebe ◽  
H. A. Quadri
Keyword(s):  
Northern Region ◽  
Design Guidelines ◽  
Traffic Volume ◽  
Southern Region ◽  
Heavy Vehicle ◽  
Heavy Vehicles ◽  
Passenger Cars ◽  
The Road ◽  
Equivalency Factors ◽  
On The Road

The prevalence of flexible pavement deterioration in the country has been adduced largely by highway researchers to trucks or heavy vehicles carrying much in excess of permitted legal limits. This study investigated levels of deterioration of Abuja-Kaduna-Kano road (Northern region) and Port Harcourt-Enugu road (Southern region) caused by heavy vehicles through a 14 day traffic counts conducted at 5 strategic points each in the Northern and Southern regions. Traffic data generated were analyzed with AASHTO Design Guidelines (1993) to evaluate Equivalent Single Axle Loads (ESALs) and Vehicle Damage effects on the road. The Traffic Volume, Average Daily Traffic (ADT), and Heavy Vehicle per day (HV/day) were estimated to be 2,063,977; 147,427; and 12,246 respectively in the Northern region, while in the Southern region they were estimated to be 750,381; 53,670; and 20,951 respectively. Motorcycles, Passenger cars, Mini-buses/Pick-ups, and Heavy vehicles constitute 18.7%, 49.7%, 23.3% and 8.31% of the total traffic volume respectively in the Northern region while in the South they constitute 4.6%, 30.1%, 26.2% and 39.1% respectively. ESALs were estimated according to AASHTO Design Guidelines in the Northern and Southern regions as 547,730 and 836,208 respectively. An average Load Equivalency Factors (LEFs) of 3.43 and 3.02 were estimated for each heavy vehicle plying the Northern and Southern roads respectively and this could explain some failures (alligator cracks, potholes, depressions, linear or longitudinal cracks along the centre line amongst others) inherent on the road.

Hard Times

Eubie Blake ◽  
2020 ◽  
pp. 217-252
Author(s):  
Richard Carlin ◽  
Ken Bloom
Keyword(s):  
United States ◽  
The United States ◽  
Publishing Company ◽  
Short Film ◽  
Big Band ◽  
The Road ◽  
Hard Times ◽  
Short Run ◽  
The Creation ◽  
On The Road

This chapter explores Eubie’s collaboration with Andy Razaf for the score of Lew Leslie’s Blackbirds of 1930; difficulties of working with Leslie; the show’s poor reception and short run on Broadway; the success of Blake and Razaf’s song, “Memories of You,” and its recording by Ethel Waters and Louis Armstrong; and the show’s troubled life on the road. The chapter further discusses Eubie’s return to working with Fanchon and Marco; Eubie’s breakup with Lottie Gee; his attempts to land work recording and on the radio; the formation of his own big band; the band’s recordings for the small Crown label; and Eubie’s difficulties dealing with his band members. Then the chapter examines Eubie’s appearance in the short film, Pie, Pie, Blackbird, with Nina Mae McKinney and the Nicholas Brothers; his breakup with Broadway Jones; Noble Sissle’s return to the United States and his reunion with Blake; the creation of Shuffle Along of 1933, with a new plot and new songs; and how Eubie briefly worked for W.C. Handy’s publishing company and published a few new songs and instrumentals with Handy.

U.S.-Israeli Policies: Reading the Signs for '77

Worldview ◽  
1976 ◽  
Vol 19 (9) ◽  
pp. 4-9
Author(s):  
Mark A. Bruzonsky
Keyword(s):  
United States ◽  
Near East ◽  
The United States ◽  
Recent Issue ◽  
The Real ◽  
The Road ◽  
Democratic Candidate ◽  
On The Road ◽  
The U.S ◽  
Sense Of Urgency

The real crunch for Israel will probably come during 1977 if Ford is elected—it will be delayed by only a few months if a Democratic candidate wins.” So writes Wolf Blitzer, editor of the “Jewish lobby's” Washington publication Near East Report, in a recent issue of the Jerusalem Post.With the same sense of urgency Abba Eban insists that “Time is of the essence, and unhappily for us, time is running out. We ought to grasp the central issues now and involve the United States in resolving them.” He and a growing number of his colleagues fear that should Israel not choose to “cooperate” with the U.S., the Americans might run right over Israel on the road to Geneva and some form of imposed settlement.

Determining Passenger Car Equivalent for Motorcycle at Mid-Block of Sesetan Road

2015 ◽  
Vol 776 ◽  
pp. 95-100
Author(s):  
I. Gusti Raka Purbanto
Keyword(s):  
Motor Vehicles ◽  
Heavy Vehicles ◽  
Highway Capacity ◽  
Passenger Car ◽  
Highway Capacity Manual ◽  
The Road ◽  
Traffic Conditions ◽  
Mode Share ◽  
Passenger Car Equivalent ◽  
On The Road

Motorcycle dominates traffic in Bali, particularly in urban roads, which occupy more than 85% of mode share. The three types of vehicles, i.e. motorcycles, heavy and light vehicles share the roadways together. Under mixed traffic conditions, motorcycle may be travelling in between and alongside two consecutive motor vehicles. Considering such a situation, passenger car equivalent values should be examined thoroughly. This study aims to determine passenger car equivalent (PCEs) of motorcycle at mid-block of Sesetan Road. Three approaches are used to examine the PCEs values. This study found that the PCE of motorcycles are in a range between 0.2 and 0.4. This values are about the same to the existing PCE of the Indonesian Highway Capacity Manual (1997). This study also pointed out that motorcyclists and car drivers may behave differently to the existence of motorcycles. Car drivers are more aware than motorcyclists on the existence of motorcycle on the road. Further, more samples are required to obtain comprehensive results. In addition, the presence of heavy vehicles need to be considered for future study.

Literary History on the Road: Transatlantic Crossings and Transpacific Crossovers

PMLA ◽  
2004 ◽  
Vol 119 (1) ◽  
pp. 92-102 ◽  
Author(s):  
Takayuki Tatsumi
Keyword(s):  
United States ◽  
World War I ◽  
American Literature ◽  
Herman Melville ◽  
Literary History ◽  
The United States ◽  
Jazz Age ◽  
The Road ◽  
History Of ◽  
On The Road

Literary history has always mirrored discursive revolutions in world history. In the United States, the Jazz Age would not have seen the Herman Melville revival and the completion of Carl Van Doren's The Cambridge History of American Literature (1917–21) without the rise of post–World War I nativism. If it had not been for Pearl Harbor, F. O. Matthiessen's American Renaissance (1941) could not have fully aroused the democratic spirit embedded in the heritage of New Criticism. Likewise, the postcolonial and New Americanist climate around 1990, that critical transition at the end of the cold war, brought about the publication of Emory Elliott's The Columbia Literary History of the United States (1988) and Sacvan Bercovitch's The Cambridge History of American Literature (1994–). I would like to question, however, the discourse that narrates American literary history in the globalist age of the twenty-first century.

A First Investigation of Truck Drivers’ Preferences and Behaviors using a Prototype Cooperative Adaptive Cruise Control System

2018 ◽  
Vol 2672 (34) ◽  
pp. 39-48 ◽  
Author(s):  
Shiyan Yang ◽  
Steven E. Shladover ◽  
Xiao-Yun Lu ◽  
Hani Ramezani ◽  
Aravind Kailas ◽  
...  
Keyword(s):  
Adaptive Cruise Control ◽  
Aerodynamic Drag ◽  
Truck Drivers ◽  
Cruise Control ◽  
Fuel Savings ◽  
The Road ◽  
Cooperative Adaptive Cruise Control ◽  
And Behaviors ◽  
On The Road ◽  
And Performance

Cooperative adaptive cruise control (CACC) is a driver-assist technology that uses vehicle-to-vehicle wireless communication to realize faster braking responses in following vehicles and shorter headways compared with adaptive cruise control. This technology not only enhances road safety, but also offers fuel savings benefits as a result of reduced aerodynamic drag. The amount of fuel savings is dictated by the following distances and the driving speeds. So, the overarching goal of this work is to explore driving preferences and behaviors when following in “CACC mode,” an area that remains largely unexplored. While in CACC mode, the brake and throttle actions are automated. A human factors study was conducted to investigate truck drivers’ experiences and performance using CACC at shorter-than-normal vehicle following time gaps. “On-the-road” experiments were conducted by recruiting drivers from commercial fleets to operate the second and third trucks in a three-truck CACC string. The driving route spanned 160 miles on freeways in Northern California and five different time gaps between 0.6 and 1.8 seconds were tested. Factors such as cut-ins by other vehicles, road grades, and traffic conditions were found to influence the drivers’ opinions about use of CACC. The findings presented in this paper provide insights into the factors that will influence driver reactions to the deployment of CACC in their truck fleets.

Analysis of Dynamic Load Level of High-Speed Heavy Vehicle Imposed on Uneven Pavement

2011 ◽  
Vol 138-139 ◽  
pp. 146-152
Author(s):  
Guo He Guo ◽  
Yu Feng Bai ◽  
Tao Wang
Keyword(s):  
Dynamic Load ◽  
High Speed ◽  
Load Level ◽  
Heavy Vehicle ◽  
Vehicle Speed ◽  
Destructive Effect ◽  
The Road ◽  
Wide Range ◽  
On The Road ◽  
Factor Interaction

Based on the significant destructive effect of heavy vehicle on uneven roads, two simplified models of pavement unevenness and vehicle dynamic load were established in accordance with D'A lembert principle, and Matlab software was used to analyze the changing law of dynamic load under the conditions of different road unevenness, vehicle speed and load. The results show that vehicles running on uneven road may produce more cumulative damages than static load, and DLC (dynamic load coefficient) changes in wide range, maximum up to 2.0 or more; the effect of speed and load on dynamic load is complex, and due to multi-factor interaction, DLC doesn’t consistently increase or decrease with speed and load increasing. Although the dynamic load level caused by high-speed heavy vehicle is not necessarily too high, its impact on the road can not be ignored.

Gender Differences on the Road to Redemption

2016 ◽  
Vol 13 (2) ◽  
pp. 182-204 ◽  
Author(s):  
Gina Curcio ◽  
April Pattavina ◽  
William Fisher
Keyword(s):  
United States ◽  
Gender Differences ◽  
Representative Sample ◽  
The United States ◽  
Policy Implications ◽  
Criminal Offense ◽  
The Road ◽  
Nationally Representative ◽  
On The Road

Redemption research examines how much time must pass after a criminal offense before an offender is considered “redeemed.” This study adds to redemption research by using a nationally representative sample from the United States to determine whether years to redemption found in prior research replicate and will be the first to determine whether there are gender differences. We also explore factors that influence who makes it to the redemption point. Findings reveal that while men reach the redemption point after 10 years, women reach the redemption point after 4 years. Policy implications of these findings are discussed.

The World of Work and New Opportunities for Social Action

2017 ◽  
Author(s):  
James J. Lorence
Keyword(s):  
Social Action ◽  
Driving Forces ◽  
The United States ◽  
Peace Movement ◽  
The Road ◽  
The Great Depression ◽  
The World ◽  
Working People ◽  
On The Road ◽  
Economic Landscape

This chapter explores how Clinton Jencks pondered the next step on the road to radicalism. Having jettisoned any thought of a legal career, he looked for an occupational base for social action in the depths of the Great Depression, still searching for an opportunity that would sustain a determined effort to make a difference in the lives of working people and enrich their experiences by spreading God's love. The religious impulse and the peace movement remained the primary driving forces in Jencks' life and were the key motivating factors in his emergence as an ambitious leader in the organizations he headed. As he surveyed the economic landscape, he saw the United States mired in the muck of stagnation and the world steadily marching toward war as fascism rapidly spread its poison.

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