The Experts below are selected from a list of 5133 Experts worldwide ranked by ideXlab platform

Kambiz Salari - One of the best experts on this subject based on the ideXlab platform.

  • Aerodynamic Drag Reduction of class 8 heavy vehicles a full scale wind tunnel study
    2013
    Co-Authors: Jason Ortega, Kambiz Salari, A Brown, R Schoon
    Abstract:

    A wind tunnel investigation is conducted to evaluate the performance of both commerciallyavailable and prototype Aerodynamic Drag Reduction devices for modern class 8 heavy vehicles. Drag force measurements are made on three full-scale, heavy vehicle configurations at a Reynolds number of 4.6× 10 based upon the vehicle width. The wind-averaged Drag coefficient is calculated from the wind tunnel measurements and used to estimate the fuel savings afforded by individual and combinations of devices. For the tractor-trailer gap, the most effective modification is found to be reducing the gap size. Numerous trailer skirts are installed on the three heavy vehicle configurations and the resulting change in the windaveraged Drag coefficient is shown to have a nominally linear dependence upon the change in the trailer skirt area. The trailer base Drag is alleviated through the installation of boattail devices. When used in combination, the devices often provide a Reduction in Drag that is greater than the individual contribution from each device. For the best vehicle configurations, the wind-averaged Drag coefficient and the resulting estimated fuel use decrease by 0.097 to 0.150 and approximately 10000 to 15000 L per 2.012×10 m of highway mileage driven, respectively.

  • investigation of tractor base bleeding for heavy vehicle Aerodynamic Drag Reduction
    Presented at: The Aerodynamics of Heavy Vehicles II: Trucks Buses and Trains Tahoe City CA United States Aug 26 - Aug 31 2007, 2009
    Co-Authors: Jason M Ortega, Kambiz Salari, Bruce L Storms
    Abstract:

    The Drag Reduction capability of tractor base bleeding is investigated using a combination of experiments and numerical simulations. Wind tunnel measurements are made on a 1:20 scale heavy vehicle model at a vehicle width-based Reynolds number of 420,000. The tractor bleeding flow, which is delivered through a porous material embedded within the tractor base, is introduced into the tractor-trailer gap at bleeding coefficients ranging from 0.0-0.018 for two different gap sizes with and without side extenders. At the largest bleeding coefficient with no side extenders, the wind-averaged Drag coefficient is reduced by a maximum value of 0.015 or 0.024, depending upon the gap size. To determine the performance of tractor base bleeding under more realistic operating conditions, computational fluid dynamics simulations are performed on a full-scale heavy vehicle traveling within a crosswind for bleeding coefficients ranging from 0.0-0.13. At the largest bleeding coefficient, the Drag coefficient of the vehicle is reduced by 0.146. Examination of the tractor-trailer gap flow physics reveals that tractor base bleeding reduces the Drag by both decreasing the amount of free-stream flow entrained into the gap and by increasing the pressure of the tractor base relative to that of the trailer frontal surface.

  • an experimental study of tractor base bleed for heavy vehicle Aerodynamic Drag Reduction
    2009
    Co-Authors: Bruce L Storms, Jason Ortega, Kambiz Salari
    Abstract:

    A significant contributor to heavy-vehicle Aerodynamic Drag is the tractor-trailer gap, especially when operating in a crosswind. At this condition, the freestream flow turns into the tractor-trailer gap, imparting a momentum exchange to the vehicle and subsequently increasing the Aerodynamic Drag. In common use today, tractor side-extenders provide significant Drag Reduction, but they are not without problems. Frequently damaged when the tractor pivots sharply with respect to the trailer, side extenders can incur additional costs for maintenance and repair. This issue can be alleviated by shortening extenders (thereby reducing their benefit) or devising an alternative Drag-Reduction concept. One such concept is tractor base bleed, in which air-flow is vented into the tractor-trailer gap through the back of the tractor. To study this concept, a wind-tunnel study was conducted for a generic 1:20-scale tractor-trailer configuration at width-based Reynolds number of 420,000. Delivered through a porous material embedded in the tractor base, the bleed flow was varied so as to generate velocities behind the tractor ranging from zero to 10% of the freestream velocity. Configurations were studied both with and without side extenders at two different tractor-trailer separation distances.

Kevin R Cooper - One of the best experts on this subject based on the ideXlab platform.

  • full scale wind tunnel tests of production and prototype second generation Aerodynamic Drag reducing devices for tractor trailers
    SAE 2006 Commercial Vehicle Engineering Congress & Exhibition, 2006
    Co-Authors: Jason Leuschen, Kevin R Cooper
    Abstract:

    The National Research Council of Canada (NRC) has completed the second round of full-scale wind tunnel tests on Class-8 tractor-trailer combinations. The primary intent of the program is to effect a Reduction in greenhouse-gas emissions by reducing the fuel consumption of trucks through Aerodynamic Drag Reduction. Add-on Aerodynamic components developed at the NRC several decades ago have become important contenders for Drag Reduction. This program has encouraged the commercialization of these technologies and this round of tests evaluated the first commercial products. Three primary devices have been evaluated, with the combination able to reduce fuel consumption by approximately 6,667 liters (1,761 US gal) annually, based on 130,000 km (81,000 miles) traveled per tractor at a speed of 100 km/hr (62 mi/hr).

  • commercial vehicle Aerodynamic Drag Reduction historical perspective as a guide
    2004
    Co-Authors: Kevin R Cooper
    Abstract:

    The Aerodynamics development of commercial vehicles has evolved over many years. Sixty-five years ago, the Labatt Brewing Company developed a streamlined truck for advertising purposes and to provide larger capacity and higher cruising speeds, Figure 1. The success of this effort is demonstrated by the fact that while trucks of the day travelled at 35 mi/h, the Labatt truck could cruise at 50 mi/h with a fifty percent larger load. The focus today is no longer on speed, but on energy conservation. It is beneficial for a country to minimise its energy utilisation and equally beneficial for its trucking industry to make money while doing so.

  • truck Aerodynamics reborn lessons from the past
    SAE transactions, 2003
    Co-Authors: Kevin R Cooper
    Abstract:

    During the late 1970's and early 1980's considerable effort was expended in the improvement of truck Aerodynamics to reduce fuel consumption. This first-generation effort focused on Aerodynamic Drag Reduction obtained from add-on Aerodynamic aids to the cab or the trailer, from improved cab shaping and from body/trailer front-end edge rounding. Rising fuel prices have renewed interest in further Aerodynamic improvements. This paper will review past developments and show that several unused concepts offer potential as second-generation, add-on, fuel-saving technology. It will raise the issue of finding successful means for bringing them profitably into service, which will require concerted action by the trucking industry, manufacturers and government.

Bruce L Storms - One of the best experts on this subject based on the ideXlab platform.

  • investigation of tractor base bleeding for heavy vehicle Aerodynamic Drag Reduction
    Presented at: The Aerodynamics of Heavy Vehicles II: Trucks Buses and Trains Tahoe City CA United States Aug 26 - Aug 31 2007, 2009
    Co-Authors: Jason M Ortega, Kambiz Salari, Bruce L Storms
    Abstract:

    The Drag Reduction capability of tractor base bleeding is investigated using a combination of experiments and numerical simulations. Wind tunnel measurements are made on a 1:20 scale heavy vehicle model at a vehicle width-based Reynolds number of 420,000. The tractor bleeding flow, which is delivered through a porous material embedded within the tractor base, is introduced into the tractor-trailer gap at bleeding coefficients ranging from 0.0-0.018 for two different gap sizes with and without side extenders. At the largest bleeding coefficient with no side extenders, the wind-averaged Drag coefficient is reduced by a maximum value of 0.015 or 0.024, depending upon the gap size. To determine the performance of tractor base bleeding under more realistic operating conditions, computational fluid dynamics simulations are performed on a full-scale heavy vehicle traveling within a crosswind for bleeding coefficients ranging from 0.0-0.13. At the largest bleeding coefficient, the Drag coefficient of the vehicle is reduced by 0.146. Examination of the tractor-trailer gap flow physics reveals that tractor base bleeding reduces the Drag by both decreasing the amount of free-stream flow entrained into the gap and by increasing the pressure of the tractor base relative to that of the trailer frontal surface.

  • an experimental study of tractor base bleed for heavy vehicle Aerodynamic Drag Reduction
    2009
    Co-Authors: Bruce L Storms, Jason Ortega, Kambiz Salari
    Abstract:

    A significant contributor to heavy-vehicle Aerodynamic Drag is the tractor-trailer gap, especially when operating in a crosswind. At this condition, the freestream flow turns into the tractor-trailer gap, imparting a momentum exchange to the vehicle and subsequently increasing the Aerodynamic Drag. In common use today, tractor side-extenders provide significant Drag Reduction, but they are not without problems. Frequently damaged when the tractor pivots sharply with respect to the trailer, side extenders can incur additional costs for maintenance and repair. This issue can be alleviated by shortening extenders (thereby reducing their benefit) or devising an alternative Drag-Reduction concept. One such concept is tractor base bleed, in which air-flow is vented into the tractor-trailer gap through the back of the tractor. To study this concept, a wind-tunnel study was conducted for a generic 1:20-scale tractor-trailer configuration at width-based Reynolds number of 420,000. Delivered through a porous material embedded in the tractor base, the bleed flow was varied so as to generate velocities behind the tractor ranging from zero to 10% of the freestream velocity. Configurations were studied both with and without side extenders at two different tractor-trailer separation distances.

Jason Ortega - One of the best experts on this subject based on the ideXlab platform.

  • Aerodynamic Drag Reduction of class 8 heavy vehicles a full scale wind tunnel study
    2013
    Co-Authors: Jason Ortega, Kambiz Salari, A Brown, R Schoon
    Abstract:

    A wind tunnel investigation is conducted to evaluate the performance of both commerciallyavailable and prototype Aerodynamic Drag Reduction devices for modern class 8 heavy vehicles. Drag force measurements are made on three full-scale, heavy vehicle configurations at a Reynolds number of 4.6× 10 based upon the vehicle width. The wind-averaged Drag coefficient is calculated from the wind tunnel measurements and used to estimate the fuel savings afforded by individual and combinations of devices. For the tractor-trailer gap, the most effective modification is found to be reducing the gap size. Numerous trailer skirts are installed on the three heavy vehicle configurations and the resulting change in the windaveraged Drag coefficient is shown to have a nominally linear dependence upon the change in the trailer skirt area. The trailer base Drag is alleviated through the installation of boattail devices. When used in combination, the devices often provide a Reduction in Drag that is greater than the individual contribution from each device. For the best vehicle configurations, the wind-averaged Drag coefficient and the resulting estimated fuel use decrease by 0.097 to 0.150 and approximately 10000 to 15000 L per 2.012×10 m of highway mileage driven, respectively.

  • an experimental study of tractor base bleed for heavy vehicle Aerodynamic Drag Reduction
    2009
    Co-Authors: Bruce L Storms, Jason Ortega, Kambiz Salari
    Abstract:

    A significant contributor to heavy-vehicle Aerodynamic Drag is the tractor-trailer gap, especially when operating in a crosswind. At this condition, the freestream flow turns into the tractor-trailer gap, imparting a momentum exchange to the vehicle and subsequently increasing the Aerodynamic Drag. In common use today, tractor side-extenders provide significant Drag Reduction, but they are not without problems. Frequently damaged when the tractor pivots sharply with respect to the trailer, side extenders can incur additional costs for maintenance and repair. This issue can be alleviated by shortening extenders (thereby reducing their benefit) or devising an alternative Drag-Reduction concept. One such concept is tractor base bleed, in which air-flow is vented into the tractor-trailer gap through the back of the tractor. To study this concept, a wind-tunnel study was conducted for a generic 1:20-scale tractor-trailer configuration at width-based Reynolds number of 420,000. Delivered through a porous material embedded in the tractor base, the bleed flow was varied so as to generate velocities behind the tractor ranging from zero to 10% of the freestream velocity. Configurations were studied both with and without side extenders at two different tractor-trailer separation distances.

Antonio Filippone - One of the best experts on this subject based on the ideXlab platform.

  • fuel savings on a heavy vehicle via Aerodynamic Drag Reduction
    Transportation Research Part D-transport and Environment, 2010
    Co-Authors: Zulfaa Mohamedkassim, Antonio Filippone
    Abstract:

    Abstract In this numerical study, the fuel-saving potentials of Drag-reducing devices retrofitted on heavy vehicles are analysed. Realistic on-road operations are taken into account by simulating typical driving routes on long-haul and urban distributions; variations in vehicle weight are also considered. Results show that the performance of these Aerodynamic devices depend both on their functions and how the vehicles are operated. Vehicles on long-haul routes generally save twice as much fuel as those driven in urban areas. The fuel Reductions from using selected devices individually on a large truck range from less than 1% to almost 9% of the fuel cost of a vehicle doing an annual mileage is 80,000 miles.