Technologies and Approaches to Reducing the Fuel Consumption of Medium- and Heavy-Duty Vehicles (2010) / Chapter Skim
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5 Vehicle Technologies for Reducing Load-Specific Fuel Consumption
5 Vehicle Technologies for Reducing Load-Specific Fuel Consumption
Pages 91-130
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From page 91... ...
21st Century Truck Partnership Technolnamic performance and reduce rolling resistance, whereas a ogy Roadmap (DOE, 2006) provides the following tables Class 2b pickup truck will benefit little from these technolo for energy losses.
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From page 92... ...
The following sections break down these areas of losses Engine losses per hour 73.1 98.0 as follows: aerodynamics, auxiliary loads, rolling resistance, Auxiliary loads 1.5 2.0 vehicle mass (weight) , and idle reduction.
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From page 93... ...
See Figure 5-5 for identification of T-600 included features such as a streamlined hood and fend- the common aerodynamic features. ers, an aerodynamic faired bumper, fuel tank fairings, and FIGURE 5-3 National Research Council of Canada: Smoke pictures, cab with deflector (right)
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From page 94... ...
Figure 5-4 Kenworth 1985 T600 aerodynamic tractor.eps bitmap J1263. This standard allows estimation of both the Early Efforts Toward Engineering Measurements coefficient of aerodynamic drag, Cd, and the rolling The development of aerodynamic features led to a need resistance coefficient, Crr.
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From page 95... ...
. As noted in Chapter 3, California adopted the SmartWay Figure 5-7 also shows the curve for power consumed by specification and validation processes as integral to its Global tire rolling resistance.
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From page 96... ...
CARB has taken this issue into account shows, aerodynamic drag is larger than rolling resistance in its greenhouse gas (GHG) regulation, where drayage tracat speeds above 48 mph for a typical current truck.
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From page 97... ...
bitmap "base" fairing, which are all illustrated in Figure 5-8, along Shorter-haul operators tend to avoid aerodynamic fairings with the approximate fuel consumption reductions that seem because they provide limited fuel savings and are prone to to be achievable in the near term. damage in urban operations and during frequent stops at loading docks.
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From page 98... ...
cause of the fragility of aerodynamic features and because A 2-year collaborative study of a variety of design imof restricted maneuverability. The other issue is that tractors provements that would reduce aerodynamic drag on tractor specified for short-haul operations will be less efficient if trailers was completed in 2007 by four members of the Truck they are pressed into long-haul service for any reason.
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From page 99... ...
Certain engine efficiency design namic improvements must be amortized over many fewer features are mentioned in Chapter 4 that might reduce the miles than is the case for tractors. The third impediment is size of current truck cooling system components and/or basic the reality that there are no aerodynamic-system integrators TABLE 5-6 Current Van Trailer Aero-Component Performance Trailer Aerodynamic Technology Skirts Boat Tails Nose Cone Vortex Stabilizer Bogie Cover Range of fuel economy improvement (% mpg)
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From page 100... ...
For the ing surfaces used on the trailer's rear face. Reported results most part it falls to the carriers themselves to sort through the indicate that a fuel consumption reduction of about 8 peremerging aerodynamic devices to find the most cost effective cent at 65 mph may be achievable with this process.
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From page 101... ...
Figure 5-11 ATDynamics trailer tail and FreightWing trailer.eps 1 bitmap with 2 clipping paths FIGURE 5-12 Nose cone trailer "eyebrow." SOURCE: Photo provided with permission by FitzGerald Corporation, national marketer for Nose Cone Mfg.
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From page 102... ...
. Figure 5-14 Trailer bogie cover.eps automatically lowers its trailer skirt as a function of road bitmapare numerous testimonials that trailer skirts and boat tails speed from 16 to 6 in.
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From page 103... ...
Boat tails can add up to 200 lb to the trailer. Like- provement in system performance (1 percent fuel savings wise, nose cones and/or vortex stabilizers can add up to 100 for full gap closure on an SAE J1321 test at 65 mph; TMA, lb weight.
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From page 104... ...
These skirts included trailer and tractor axle While the dry van constitutes the largest portion of body skirts. The fuel consumption reduction of the combination styles in the U.S.
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From page 105... ...
One trailer aerodynamics supplier, Freight tanker-trailer applications. Trailer skirts can be fitted as the Wing, has fitted a flatbed with a skirt but has not yet tested dry van.
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From page 106... ...
Figure 5-22 Tank trailer with freight wing skirts.eps bitmap FIGURE 5-21 Container chassis with Freight 5-21 Container chassis Wing. freight Wing trailer skirt.skir.eps Figure with wing trailer SOURCE: Courtesy of Freight bitmap
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From page 107... ...
The three features were a 24-ft long of doubling the fuel economy of its (then) 7,200-tractor trailer skirt with 9-in.
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From page 108... ...
As such, the estimates of motor coach solutions found on van trailers. Nose cones have been widely aerodynamic drag reduction potential in this report are based applied, but little or no SAE J1321 data are available (see on extending results of the line-haul analysis to the motor Figure 5-26)
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From page 109... ...
Figure 5-27 Freight wing skirt on straight truck.eps bitmap The NHTSA rulemaking considered underbody treatdynamic drag. Boat tails on a tractor trailer are assumed to reduce drag by 6 to 9 percent and to offer fuel consumption ments; streamlined hood, windshield, fenders, and grill; re benefits of 3 to 5 percent.
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From page 110... ...
"Heavy Duty Trucks SOURCE: Society of Automotive Engineers (SAE) J1343, "Information Fuel Economy Technology," presentation to the committee, December 5, Relating to Duty Cycles and Average Power Requirements of Truck and 2008, Washington, D.C., Slide 23.
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From page 111... ...
As seen in Figure 5-30, dual tires span a range the mechanical power requirement from the engine to drive of Crr and can also qualify as low rolling resistance per the SmartWay definition.7 auxiliaries will not necessarily be a one-to-one reduction in fuel consumption. In general, reducing the load on the Replacement of typical dual tires with NGWBS tires can engine will also result in a decrease in the engine's thermal give fuel economy improvements approaching 10 percent efficiency.
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From page 112... ...
28580 standardized test method for tire rolling resistance measurement. The tire industry has been working recently to develop this test standard, which is applicable to new passenger car, truck, and bus tires.
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From page 113... ...
. TABLE 5-13 Results of Truck Model Showing Effect of Additionally, rollover performance with NGWBS tires has Coefficient of Rolling Resistance, Crr, on Fuel Economy been shown to be similar to or improved relative to dual-tire for Several Drive Cycles rollover performance (Knee et al., 2008)
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From page 114... ...
Camber effects, by comparison, are relatively systems (TPMSs) can help improve the fuel consumption small on rolling resistance, and the slip angle impact is thus and safety of heavy trucks by ensuring that adequate pressure the only alignment effect considered here.
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From page 115... ...
Given the large fuel use in Class 8 trucks, coupled with the large impact of rolling resistance, most information about tire Rolling Resistance Summary effects has been quantified only for this class. Lower vehicle loads result in a reduction in the total rolling resistance, and TIAX, in its report for the committee, summarized the the relative impact that tires have on fuel economy therefore rolling resistance fuel consumption potential reduction by decreases for vehicles with lower mass (see estimates of range of years and by application in Table 5-14.
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From page 116... ...
-6,000 2,400-5,000 1,000 20 tire rolling resistance and unrecovered energy used when 1t 0(4,000) -6,000 3,200-4,500 1,500 33 accelerating or grade climbing.
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From page 117... ...
. Figure 5-32 Weight distribution of major component categorie.eps bitmap -- resolution too low, degraded legibility Total Class 7/8 Tractor Weights Conventional/Day Cab: 11,000-12,000 lbs Conventional/Sleeper Cab: 16,000-18,000 lbs FIGURE 5-33 Typical weights of specific components in Class 8 sleeper tractors.
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From page 118... ...
SOURCE: New West Technologies. Figure 5-35 Truck weight distribution from 2008 weight in mot.eps low-resolution bitmap -- legibility is degraded Another advantage of weight reduction technology is These data and similar information from numerous other the ability afforded the truck manufacturer to maintain the sources are summarized in Table 5-16 for a wide range of axleload limits imposed by regulation.
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From page 119... ...
FIGURE 5-37. Effect of weight on truck fuel economy for a monitored fleet of six trucks with combination of dual and wide single tires for a variety of drive routes.
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From page 120... ...
hybrid cycle; mostly city and suburb, favors hybridization Bus, 40 ft 35k baseline, ~2.0% fuel consumption reduction per Central business district cycle NREL (2002, 2004) conventional drivetrain 1000 lb 1.66 percent fuel economy gain per 10 Hybrid IFEU (2003)
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From page 121... ...
other waste heat recovery, 240 lb and up Hybridization can eliminate transmission and Batteries offset weight mechanical pumps and alternator savings, 200-2000 lb Sullivan, 2007a 21st Century Truck Partnership agreed on goal of 20% weight reduction Recent Volvo press release says 20% reduced FleetOwner (2009) weight feasible in 10 years 25% weight reduction estimate by American Transport Topics (2009)
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From page 122... ...
Duleep, Energy and Environmental Analysis, "Heavy Duty Trucks sumption improvement as conventional APUs. Fuel Economy Technology," presentation to the committee, Washington, D.C., December 5, 2008.
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From page 123... ...
As discussed in the National Research Council's in" to power heaters, air conditioners, lights, and other ac (NRC's) review of the DOE 21st Century Truck Partnership (NRC, 2008)
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From page 124... ...
to 800 hours per year. SmartWay estimates 800 hours per year of heater fuel use.15 TABLE 5-23 Comparison of Truck Stop Electrification INTELLIGENT VEHICLE TECHNOLOGIES Systems IVT combines information about the state of the veSupplier Cost ($)
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From page 125... ...
The band is also eligible The driver must therefore revert to manual control. ACC has for use by nonpublic safety entities for commercial or private fuel economy benefits because, even in traffic, all acceleraDSRC operations.
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From page 126... ...
This concept utilizes real-time traffic informafessional drivers and 10 passenger cars equipped with ACC tion to anticipate changes in traffic speed and then adjusts in southeast Michigan (Koziel et al., 1999) indicated a 10 the set cruise speed accordingly to reduce large accelerations percent fuel consumption reduction compared with manual and decelerations.
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From page 127... ...
show a fuel economy improvement of 3 to 9 percent the trail truck and 5 to 10 percent for the lead truck, with the versus nonpredictive control. The SENTIENCE program larger values of savings occurring at the shorter spacing.
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From page 128... ...
In low-speed operation, the coefficient of rolling resistance is recommended to aid aerodynamic features have little value. consumer selection, similar to that proposed for passenger Finding 5-2.
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From page 129... ...
2009. Truck Tires and Rolling Resistance: IFEU (Institut für Energieund Umweltforschung, Heidelberg GmbH)
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From page 130... ...
Pre of Transportation, National Highway Traffic Safety Administration. sentation at the Tire Rolling Losses and Fuel Economy -- An R&D Lattermann, F., K
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