Problem 3. A tractor-trailer rig has a frontal area of A = 102 ft² and drag coefficient CD = 0.9. The ratio of rolling resistance to vehicle weight is CR = FR/W = (6 lbf)/(1000 lbf). The specific fuel consumption (defined as mass of fuel consumed divided by power, or thrust, produced times the time period) for the diesel engine is SFC= mƒ/(P▲t) = 0.34 lbm/(hp hr) and the drivetrain efficiency is na = 92%. The density of diesel fuel is pf = 6.9 lbm/gal. (a) Estimate the fuel economy, FE, for a rig traveling at a speed of U = 55 mph with a weight of W = 72,000 lbs. (b) For a fairing system that reduces the aerodynamic drag by 15%, estimate the improved fuel economy, FE faired. (c) Calculate the annual fuel savings, FS, for a rig that travels 120,000 miles per year. (d) Plot FE and FEƒ faired versus speed, U, assuming SFC and nd are constant.
Problem 3. A tractor-trailer rig has a frontal area of A = 102 ft² and drag coefficient CD = 0.9. The ratio of rolling resistance to vehicle weight is CR = FR/W = (6 lbf)/(1000 lbf). The specific fuel consumption (defined as mass of fuel consumed divided by power, or thrust, produced times the time period) for the diesel engine is SFC= mƒ/(P▲t) = 0.34 lbm/(hp hr) and the drivetrain efficiency is na = 92%. The density of diesel fuel is pf = 6.9 lbm/gal. (a) Estimate the fuel economy, FE, for a rig traveling at a speed of U = 55 mph with a weight of W = 72,000 lbs. (b) For a fairing system that reduces the aerodynamic drag by 15%, estimate the improved fuel economy, FE faired. (c) Calculate the annual fuel savings, FS, for a rig that travels 120,000 miles per year. (d) Plot FE and FEƒ faired versus speed, U, assuming SFC and nd are constant.
Elements Of Electromagnetics
7th Edition
ISBN:9780190698614
Author:Sadiku, Matthew N. O.
Publisher:Sadiku, Matthew N. O.
ChapterMA: Math Assessment
Section: Chapter Questions
Problem 1.1MA
Related questions
Question

Transcribed Image Text:Problem 3. A tractor-trailer rig has a frontal area of A = 102 ft² and drag coefficient CD = 0.9. The ratio of
rolling resistance to vehicle weight is CR = FR/W = (6 lbf)/(1000 lbf). The specific fuel consumption
(defined as mass of fuel consumed divided by power, or thrust, produced times the time period) for the diesel
engine is SFC= mƒ/(P▲t) = 0.34 lbm/(hp hr) and the drivetrain efficiency is na = 92%. The density
of diesel fuel is pf = 6.9 lbm/gal. (a) Estimate the fuel economy, FE, for a rig traveling at a speed of
U = 55 mph with a weight of W = 72,000 lbs. (b) For a fairing system that reduces the aerodynamic drag by
15%, estimate the improved fuel economy, FE faired. (c) Calculate the annual fuel savings, FS, for a rig that
travels 120,000 miles per year. (d) Plot FE and FEƒ
faired versus speed, U, assuming SFC and nd are
constant.
Expert Solution

This question has been solved!
Explore an expertly crafted, step-by-step solution for a thorough understanding of key concepts.
Step by step
Solved in 2 steps

Recommended textbooks for you

Elements Of Electromagnetics
Mechanical Engineering
ISBN:
9780190698614
Author:
Sadiku, Matthew N. O.
Publisher:
Oxford University Press

Mechanics of Materials (10th Edition)
Mechanical Engineering
ISBN:
9780134319650
Author:
Russell C. Hibbeler
Publisher:
PEARSON

Thermodynamics: An Engineering Approach
Mechanical Engineering
ISBN:
9781259822674
Author:
Yunus A. Cengel Dr., Michael A. Boles
Publisher:
McGraw-Hill Education

Elements Of Electromagnetics
Mechanical Engineering
ISBN:
9780190698614
Author:
Sadiku, Matthew N. O.
Publisher:
Oxford University Press

Mechanics of Materials (10th Edition)
Mechanical Engineering
ISBN:
9780134319650
Author:
Russell C. Hibbeler
Publisher:
PEARSON

Thermodynamics: An Engineering Approach
Mechanical Engineering
ISBN:
9781259822674
Author:
Yunus A. Cengel Dr., Michael A. Boles
Publisher:
McGraw-Hill Education

Control Systems Engineering
Mechanical Engineering
ISBN:
9781118170519
Author:
Norman S. Nise
Publisher:
WILEY

Mechanics of Materials (MindTap Course List)
Mechanical Engineering
ISBN:
9781337093347
Author:
Barry J. Goodno, James M. Gere
Publisher:
Cengage Learning

Engineering Mechanics: Statics
Mechanical Engineering
ISBN:
9781118807330
Author:
James L. Meriam, L. G. Kraige, J. N. Bolton
Publisher:
WILEY