Friction Reduction Trends in Modern Engines

Nam, Edward K.; Sorab, Jagadish

doi:10.4271/2004-01-1456

Cited by 9 publications

(5 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The engine overall efficiency equation above does not include any friction term related to engine speed but constant friction mean effective pressure (fmep) at idling so engine efficiency remains constant at a given engine torque. This simple approach is useful for normal engine operating conditions because most of gasoline engines do not have significant change of efficiency by fmep at a given engine torque in the operating region used in this study [49].…”

Section: Simple Vehicle Modeling For a Conventional Vehiclementioning

confidence: 99%

“…In order to find the fuel rate of the vehicle, engine overall efficiency and power of fuel should be obtained. The engine overall efficiency can be obtained from equation (3.16) which is simplified from the study done by Nam and Sorab [49]. The engine overall efficiency equation above does not include any friction term related to engine speed but constant friction mean effective pressure (fmep) at idling so engine efficiency remains constant at a given engine torque.…”

Section: Simple Vehicle Modeling For a Conventional Vehiclementioning

confidence: 99%

See 1 more Smart Citation

Vehicle Inertia Impact on Fuel Consumption of Conventional and Hybrid Electric Vehicles Using Acceleration and Coast Driving Strategy

Lee

Nelson

Lohse-Busch³

2009

SAE Technical Paper Series

View full text Add to dashboard Cite

In the past few years, the price of petroleum based fuels, especially vehicle fuels such as gasoline and diesel, has been increasing at a significant rate. Consequently, there is much more consumer interest related to reducing fuel consumption for conventional vehicles and hybrid electric vehicles (HEVs) than in the past.The goal of many competitions and challenges held in North America and Europe is to achieve extremely low fuel consumption. A possible strategy to reduce fuel consumption is to use the vehicle's fuel converter such as an engine to accelerate the vehicle to a high speed and coast to a lower speed with the engine off. This method will reduce fuel flow to zero during the coast phase. Also, the vehicle uses higher power engine load to accelerate to the upper vehicle speed in a limited time, thus increasing the engine brake thermal efficiency. This strategy is known as "pulse and glide" or "burn and coast" in some references.In this study, the "pulse and glide" (PnG) method is first applied to a conventional vehicle to quantify the fuel consumption benefits when compared to steady speed conditions over the same distance. After that, an HEV is used as well to investigate if a hybrid system can further reduce fuel consumption with the proposed strategy. Note that the HEV used in this study has the advantage that the engine can be automatically shut off below a certain speed (~40 mph) at low loads, however a driver must shut off the engine manually in a conventional vehicle to apply this driving strategy.iii In this document, three preliminary results of the PnG driving strategy are presented; (1) improved fuel economy for a conventional vehicle from a simple spread sheet model, (2) improved fuel economy for an HEV from a dynamic vehicle simulation model (the Powertrain Analysis Toolkit (PSAT)) and (3) improved fuel economy for an HEV from vehicle testing at Argonne National Laboratory (ANL), all compared to steady speed conditions. The preliminary results show that the impact of engine load and kinetic energy stored in vehicle inertia is significant for fuel consumption using a PnG driving strategy compared to steady speed driving at the same average speed case. Especially, fuel economy can be improved at low speed range and higher acceleration because the aerodynamic drag force is smaller at low speed and the engine is running in a more efficient region for a short period of time respectively. In the last section, proposed directions of research are addressed based on the preliminary results.iv

show abstract

Section: Simple Vehicle Modeling For a Conventional Vehiclementioning

confidence: 99%

Section: Simple Vehicle Modeling For a Conventional Vehiclementioning

confidence: 99%

Vehicle Inertia Impact on Fuel Consumption of Conventional and Hybrid Electric Vehicles Using Acceleration and Coast Driving Strategy

Lee

Nelson

Lohse-Busch³

2009

SAE Technical Paper Series

View full text Add to dashboard Cite

show abstract

“…The origin of this result is unclear. While engine friction has been reduced by approximately 20% since initial formulation of the Ross model [ Nam and Sorab , ], this reduction is not sufficient to explain the observed discrepancy nor are changes in the motor vehicle fleet sufficient. While the hybridization of the Bay Area fleet leads the nation, present sales account for only approximately 10% of passenger cars, and gasoline/electric hybrids are only a factor of 2–4 more efficient than conventional vehicles, even under stop‐and‐go conditions [ Fontaras et al , ].…”

Section: Results and Analysismentioning

confidence: 99%

Estimates of CO₂ traffic emissions from mobile concentration measurements

et al. 2015

View full text Add to dashboard Cite

We present data from a new mobile system intended to aid in the design of upcoming urban CO 2 -monitoring networks. Our collected data include GPS probe data, video-derived traffic density, and accurate CO 2 concentration measurements. The method described here is economical, scalable, and self-contained, allowing for potential future deployment in locations without existing traffic infrastructure or vehicle fleet information. Using a test data set collected on California Highway 24 over a 2 week period, we observe that on-road CO 2 concentrations are elevated by a factor of 2 in congestion compared to free-flow conditions. This result is found to be consistent with a model including vehicle-induced turbulence and standard engine physics. In contrast to surface concentrations, surface emissions are found to be relatively insensitive to congestion. We next use our model for CO 2 concentration together with our data to independently derive vehicle emission rate parameters. Parameters scaling the leading four emission rate terms are found to be within 25% of those expected for a typical passenger car fleet, enabling us to derive instantaneous emission rates directly from our data that compare generally favorably to predictive models presented in the literature. The present results highlight the importance of high spatial and temporal resolution traffic data for interpreting on-and near-road concentration measurements. Future work will focus on transport and the integration of mobile platforms into existing stationary network designs.

show abstract

“…As described earlier, gasoline engine performance is very consistent even for different manufacturers and engine sizes. It has been found that the indicated efficiency has not changed significantly over the preceding 3 decades [30], as shown in Fig. 2.…”

Section: Perementioning

confidence: 86%

Development of Fleet Energy Savings Evaluation Tools for Smart Mobility: Smart Vehicle Energy Technology (SVET) Model for Passenger Fleets and Freight Fleet Level Energy Estimation Tool (FFLEET) for Freight Fleets

LaClair

Moore

2018

View full text Add to dashboard Cite

Friction Reduction Trends in Modern Engines

Cited by 9 publications

References 8 publications

Vehicle Inertia Impact on Fuel Consumption of Conventional and Hybrid Electric Vehicles Using Acceleration and Coast Driving Strategy

Vehicle Inertia Impact on Fuel Consumption of Conventional and Hybrid Electric Vehicles Using Acceleration and Coast Driving Strategy

Estimates of CO₂ traffic emissions from mobile concentration measurements

Development of Fleet Energy Savings Evaluation Tools for Smart Mobility: Smart Vehicle Energy Technology (SVET) Model for Passenger Fleets and Freight Fleet Level Energy Estimation Tool (FFLEET) for Freight Fleets

Contact Info

Product

Resources

About

Friction Reduction Trends in Modern Engines

Cited by 9 publications

References 8 publications

Vehicle Inertia Impact on Fuel Consumption of Conventional and Hybrid Electric Vehicles Using Acceleration and Coast Driving Strategy

Vehicle Inertia Impact on Fuel Consumption of Conventional and Hybrid Electric Vehicles Using Acceleration and Coast Driving Strategy

Estimates of CO2 traffic emissions from mobile concentration measurements

Development of Fleet Energy Savings Evaluation Tools for Smart Mobility: Smart Vehicle Energy Technology (SVET) Model for Passenger Fleets and Freight Fleet Level Energy Estimation Tool (FFLEET) for Freight Fleets

Contact Info

Product

Resources

About

Estimates of CO₂ traffic emissions from mobile concentration measurements