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Viewing 1 to 30 of 2565
2015-10-06
Event
This session will address aerodynamic testing requirements, technologies, facilities, and methods with a view toward improving efficiency and reducing emissions of medium and heavy commercial ground vehicles. Specific topics to be discussed are aerodynamic related corrections, correlations and assessments for various data sources including wind tunnel, CFD, and on-track/road testing.
2015-10-06
Event
For aerodynamic technology to mature it is critical that the use of aerodynamic tools is based on critical governing aerodynamic and fluid dynamic criteria. In aerodynamics the most critical criteria is Reynolds number. Specific topics to be discussed are guidance and methods for Reynolds number and boundary layer assessment, modeling and simulation for aerodynamic evaluation and operational performance of commercial vehicles.
2015-10-06
Event
Commercial vehicle aerodynamics and fuel economy are greatly affected by transient and interfering flows. As the aerodynamic sophistication of commercial vehicles increase the importance of these phenomena in vehicle design will increase. Specific topics to be discussed are guidelines and methods for the modeling and simulation of these effects in vehicle design, experimental evaluation and the operational performance of commercial vehicles.
2015-10-06
Event
The need to reduce aerodynamic drag arising from cooling and thermal flows may increase as total vehicle drag is reduced. The complexity of this problem area will require advancements in both experimental and computational tools. Specific topics to be discussed are experimental and computational results as well the correlation of data sets from various sources for both the localized flow conditions as well a complete vehicle in operation.
2015-10-06
Event
The recognition and acceptance of aerodynamics as a major player in trucking efficiency has increased significantly over the past decade. The effective integration of aerodynamic concepts and technologies into future vehicles will require a multi-disciplinary/multi-design point approach. This session will address the current status and future role of aerodynamic design methods, tools and processes.
2015-10-06
Event
The use of CFD by the commercial vehicle industry has grown significantly in the past decade. This session will address steady state and transient aerodynamic modeling and simulation with Navier-Stokes and Lattice-Boltzmann based methods with a view toward improving efficiency and reducing emissions of medium and heavy commercial ground vehicles.
2015-10-06
Event
The SuperTruck demonstration program is nearing completion. Preliminary status reports show that aerodynamic drag reduction is critical to achieving the program goal of 50% improvement in freight efficiency. This session will highlight the aerodynamic technologies and vehicle integration strategies employed in the program to optimize the benefit of aerodynamics in future vehicle design.
2015-10-06
Event
Future commercial vehicles will need to expand the use of advanced aerodynamic flow-control technologies to achieve significant levels of aerodynamic drag reduction and vehicle fuel economy improvements achieved with currently available with vehicle shaping and add-on fairings. This session will address passive and active flow control techniques for the cost effective management of aerodynamic drag with a view toward improving efficiency and reducing emissions.
2015-10-06
Event
Aerodynamic drag reduction is and will continue to be a primary means to achieving significant improvements in commercial vehicle freight efficiency. This session will review current and near term aerodynamic technology benefits and design sensitivities with a view toward improving efficiency and reducing emissions of medium and heavy commercial ground vehicles. Discussions will include data obtained from wind tunnels, on-road testing and computational tools.
2015-09-29
Technical Paper
2015-01-2890
Felix Hoffmann, Hanns-Joachim Schmidt, Christian Nayeri, Oliver Paschereit
The potential of drag reduction on a generic model of a heavy vehicle using base flaps operated in combination with passive and active flow control devices is investigated experimentally. Base flaps are well known as drag reduction devices for bluff bodies and heavy road vehicles. However, for optimal performance their deflection angle should typically not exceed 12°. The primary goal of ongoing investigations is to increase the usable range of the deflection angles by applying flow control. The secondary goal is to find the most suitable method for flow control. In this paper we compare triangular vortex generators and fluidic oscillators as passive and active flow control methods, respectively. These methods are used on declined surfaces or airfoils for shifting flow separation towards higher deflection angles. Vortex generators have the advantage of being very simple devices but produce drag. Fluidic oscillators are also quite simple devices but require additional air supply.
2015-09-29
Technical Paper
2015-01-2886
Kebing Tang, Li He, Yao Zhao
The development of a new Dongfeng Heavy truck had very strict targets for fuel consumption. As the aerodynamic drag plays a crucial role for the fuel consumption, a low drag value had to be achieved. It was therefore essential to include evaluation and optimization of the aerodynamics in the development process. Because wind tunnel facilities were not available, the complete aerodynamics development was based on digital simulation. The major portion of the aerodynamic optimization was carried out during the styling phase where mirrors, sun visor, front bumper and aero devices were optimized for drag reduction. For optimizing corner vanes and mud guards, self-soiling from the wheel spray was included in the analysis. The aero results did also show that cooling air flow rates are sufficiently high to ensure proper cooling. During the detailed engineering phase an increase of the drag above the target required further optimization work to finally reach the target.
2015-09-29
Technical Paper
2015-01-2859
Richard Wood
ABSTRACT
2015-09-29
Technical Paper
2015-01-2895
Prasad Vegendla, Tanju Sofu, Rohit Saha, Mahesh Madurai Kumar, Long-Kung Hwang
This paper investigates the aerodynamic influence of multiple on-highway trucks in different platooning configurations. Complex pressure fields are generated on the highways due to interference of multiple vehicles. This pressure field causes an aerodynamic drag to be different than the aerodynamic drag of vehicle in no traffic condition. In order to study, the effect of platooning, three-dimensional modeling and numerical simulations are performed using STAR-CCM+® commercial Computational Fluid Dynamics (CFD) tool. The aerodynamic characteristics of vehicles are analyzed in five different platooning configurations with two and three vehicles in single and multiple lanes. A significant Yaw Averaged Aerodynamic Drag (YAD) reduction is observed in both leading and trailing vehicles. It is noted that YAD is based on the average result of three different yaw angles at 0, -6 and 6o. In single lane traffic, YAD reduction is up to 8% and 38% in leading and trailing vehicles, respectively.
2015-09-29
Technical Paper
2015-01-2896
Matthew Ellis, Joaquin Ivan Gargoloff, Raja Sengupta
The increasing importance of reducing greenhouse gas emissions and the ongoing evolution of vehicle-to-vehicle connectivity technologies have generated significant interest in platooning for commercial vehicles, where two or more vehicles travel in same traffic lane in relatively close proximity. This paper examines the effect of platooning on four increasingly aerodynamic tractor-trailer configurations, using a Lattice Boltzmann based CFD solver. Each platoon consisted of three identical tractor-trailer configurations traveling in the same lane at 65mph. Two different vehicle to vehicle gaps were studied, 5m and 9m, in addition to singleton vehicles, representing an effectively infinite gap. Aerodynamic drag for the lead, middle, and trailing vehicle in the platooning configurations were compared to the corresponding single vehicle tractor-trailer configuration.
2015-09-29
Technical Paper
2015-01-2897
Rick Mihelic, Jeff Smith, Matthew Ellis
Modern aerodynamic Class 8 freight tractors can improve vehicle freight efficiency and fuel economy versus older traditional style tractors when pulling Canadian style A- or B-Train double trailer long combination vehicles (LCV's) at highway speeds. This paper compares the aerodynamic performance of a current generation aerodynamic tractor with several freight hauling configurations through computational fluid dynamics evaluations using the Lattice-Boltzmann methodology. The configurations investigated include the tractor hauling a standard 53' trailer, a platooning configuration with a 30' separation distance, and an A-Train configuration including two 48' trailers connected with a dolly converter. The study demonstrates CFD's capability of evaluating extremely long vehicle combinations that might be difficult to accomplish in traditional wind tunnels due to size limitations.
2015-09-29
Technical Paper
2015-01-2898
Luigi Salati, Federico Cheli, Paolo Schito
The flow-field around a “common” European heavy truck with front-rear trailer device (patent of Politecnico di Milano, 2014) is investigated using time variant simulation. When these kind of devices are mounted on the trailer it is possible to strongly decrease the aerodynamic drag over 10% with an increase of overall dimensions below 1% in width and height. These devices can be installed on every truck (next, current, previous generation - container) of any truck manufacturer no influencing the functionality of the vehicle. Detached eddy simulation (DES) with one equation Spalart-Allmaras is used as turbulence model when the Unsteady Reynolds-averaged Navier-Stokes equations are solved; while the two equation k-ω SST turbulence model is selected for the RANS simulations. All the simulation are performed using grids about 40-41 millions of elements and 25000/30000 time steps are given for a Unsteady simulation. The simulations where conducted using the yaw angle of 0°, 5°, 10°.
2015-09-29
Technical Paper
2015-01-2885
Nicholas Schaut, Raja Sengupta
As part of the United States Department of Energy’s SuperTruck program, Volvo Trucks and its partners were tasked with demonstrating 50% improvement in overall freight efficiency for a tractor-trailer, relative to a best in class 2009 model year truck. This necessitated that significant gains be made in reducing aerodynamic drag of the tractor-trailer system, so trailer side skirts and a trailer boat tail were employed. A Lattice-Boltzmann based simulation method was used in conjunction with a Kriging Response Surface optimization process in order to efficiently describe a design space of seven independent parameters relating to boat tail and side skirt dimensions, and to find an optimal configuration. In two separate phases of optimization conducted with different constraints, the most influential parameters are identified in achieving significant aerodynamic drag reduction relative to a base configuration. The result was corroborated by on-road fuel economy testing.
2015-09-23
Event
This session will cover aero Stability & Control, loads, aeroelastics & flutter, flight control laws/flying qualities.
2015-09-23
Event
General Aerodynamics topics for flight vehicles of all types, including flow physics, applied aerodynamics of wings, tails, rotors, control surfaces, aero loads and wind tunnel testing.
2015-09-23
Event
This session will cover aero Stability & Control, loads, aeroelastics & flutter, flight control laws/flying qualities.
2015-09-23
Event
This session will cover flight vehicle performance and sizing, conceptual/preliminary design, MDO, aero-propulsion integration, design education.
2015-09-23
Event
Although UAS aerodynamics is for the most part similar to that of manned aircraft, some designs requirements are unique for micro to small and high altitude, long-endurance vehicles. This session discusses critical aspects of aerodynamics for fixed and rotary wing UAS along with lighter than air technologies.
2015-09-15
Technical Paper
2015-01-2566
Reuben Chandrasekharan, Nick Iarocci, Sherry Vafa, Iyad Akel
The Learjet 85 is a business jet with an unpowered manual elevator control and is designed for a maximum dive Mach number of 0.89. During the early design, it was found that the stick force required for a 1.5g pull-up from a dive would exceed the limit set by FAA regulations. A design improvement of the tailplane was initiated, using 2D and 3D Navier-Stokes CFD codes. It was discovered that a small amount of positive camber could reduce the elevator hinge moment for the same tail download at high Mach numbers. This was the result of the stabilizer forebody carrying more of the tail download and the elevator carrying less. Consequently, the elevator hinge-moment during recovery from a high-speed dive was lower than for the original tailplane. Horizontal tails are conventionally designed with zero or negative camber since a positive camber can have adverse effects on tail stall and drag.
2015-09-15
Technical Paper
2015-01-2453
Danilo Andreoli, Mario Cassaro, Manuela Battipede, Goodarz Ahmadi, Piergiovanni Marzocca
The control of the flow over aerodynamic shapes in order to achieve performance enhancements, such as improved aircraft maneuverability, has been a lively area of research for last two decades. Active flow control can produce significant performance improvement when combined in a closed-loop control system. Synthetic jet actuators (SJAs) are devices able to interact actively with the flow around a hosting structure by providing ejection and suction of fluid from an orifice. The research presented in this paper concerns the implementation of zero-net-mass-flux SJAs airflow control system on a NACA0015, low aspect ratio (LAR) wing section prototype developed by Clarkson University under the Advancement of Intelligent Aerospace Systems (AIAS) AFOSR Grant FA9550-09-1-0051. Two arrays of custom made SJAs, installed in the proximity of the leading edge and flap of the wing section, make up the actuation system.
Viewing 1 to 30 of 2565

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