Drag Reduction Through Changes in Cabin Geometry and Trailer Gap of Heavy-Duty Trucks

Volume 1 ◽  
2004 ◽  
Author(s):  
M. Lakshman ◽  
K. Aung
Keyword(s):  
Numerical Simulations ◽  
Aerodynamic Drag ◽  
Cost Savings ◽  
Vehicle Speed ◽  
Fuel Cost ◽  
Heavy Duty ◽  
Cross Sectional ◽  
Computational Fluid Dynamics Cfd ◽  
Imported Oil ◽  
Fuel Costs

Reduction of aerodynamic drag of heavy-duty trucks can significantly save fuel costs and US dependence on the imported oil. Reduction of aerodynamic drag by 30% can result in fuel cost savings in billions of dollars every year. Aerodynamic drag of truck depends on the frontal cross-sectional area and the speed of the vehicle. In addition, the gap between the cabin and the trailer significantly affect the drag of the truck. This paper investigates how changes in the cabin geometry and the trailer gap can reduce the aerodynamic drag using numerical simulations. The numerical simulations were carried out using Computational Fluid Dynamics (CFD) software, CFX-5.5, from AEA Technologies (now owned by ANSYS). Effects of vehicle speed, cabin geometry, and trailer gap on the aerodynamic drag were investigated.

scholarly journals Aerodynamics Analysis of Speed Skating Helmets: Investigation by CFD Simulations

2021 ◽  
Vol 11 (7) ◽  
pp. 3148
Author(s):  
Guillermo Puelles Magán ◽  
Wouter Terra ◽  
Andrea Sciacchitano
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Flow Field ◽  
Numerical Simulations ◽  
Turbulence Model ◽  
Aerodynamic Drag ◽  
Cfd Simulations ◽  
Speed Skating ◽  
Computational Fluid Dynamics Cfd ◽  
Rans Simulations

In this work, we investigate the flow field around speed skating helmets and their associated aerodynamic drag by means of computational fluid dynamics (CFD) simulations. An existing helmet frequently used in competition was taken as a baseline. Six additional helmet designs, as well as the bare-head configuration, were analysed. All the numerical simulations were performed via 3D RANS simulations using the SST k-ω turbulence model. The results show that the use of a helmet always reduces the aerodynamic drag with respect to the bare head configuration. Besides, an optimised helmet design enables a reduction of the skaters aerodynamic drag by 5.9%, with respect to the bare-head configuration, and by 1.6% with respect to the use of the baseline Omega helmet.

Numerical Simulations on the Aerodynamics Drag of a Tractor With a Tandem-Trailer

2006 ◽  
Author(s):  
M. Sitlani ◽  
K. Aung
Keyword(s):  
Experimental Data ◽  
Aerodynamic Drag ◽  
Vehicle Speed ◽  
Gap Size ◽  
Heavy Duty ◽  
Heavy Duty Truck ◽  
Engine Design ◽  
Closing The Gaps ◽  
Simulation Results ◽  
Present Simulation

The aerodynamic drag characteristics of a heavy duty truck with two configurations, a tractor and a single trailer, and a tractor and a tandem-trailer (two trailers), have been studied. The aerodynamic drag of a truck depends on geometry, frontal area, and the speed of the truck. The basic geometry used in the simulation is 1:8 scale Ground Transportation System (GTS). The present simulation model has a simplified geometry of GTS with a cab-over engine design with either one or two trailers. In particular, the effects of the gap between the tractor and the trailer, and the gap between the tandem trailers on the aerodynamic drag were determined. The effects of vehicle geometry, vehicle speed, and the gap size were investigated and the drag coefficients were computed. CFD software STAR-CD with an expert tool, es-aero, was used for all the analyses reported in this paper. The simulation results were validated with available experimental data and good agreements were found for vehicle speeds at highway and city limits. The results showed that closing the gaps and incorporating boat-tails at the rear of the trailer could reduce the drag by as much as 40 percent.

Reduced Aerodynamic Drag for Truck-Trailer Configurations Using Parametrized CFD Studies

2012 ◽  
Author(s):  
Srdan Pavlović ◽  
Magnus Andersson ◽  
Jonas Lantz ◽  
Matts Karlsson
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Drag Reduction ◽  
Conceptual Design ◽  
Fuel Economy ◽  
Aerodynamic Drag ◽  
Foreseeable Future ◽  
Heavy Duty ◽  
Computational Fluid Dynamics Cfd

In the presented work, two studies using Computational Fluid Dynamics (CFD) have been conducted on a generic truck-like model with and without a trailer unit at a speed of 80 km/h. The purpose is to evaluate drag reduction possibilities using externally fitted devices. A first study deals with a flap placed at the back of a rigid truck and inclined at seven different angles with two lengths. Results show that it is possible to decrease drag by 4%. In a second study, the flap has been fitted on the tractor and trailer units of a truck-trailer combination. Four settings were surveyed for this investigation, one of which proved to decrease drag by up to 15%. A last configuration where the gap between the units has been closed has also been evaluated. This configuration offers a 15% decrease in drag. Adding a flap to the closed gap configuration decreases drag by 18%. New means of reducing aerodynamic drag of heavy-duty (HD) vehicles will be important in the foreseeable future in order to improve the fuel economy. The possibilities of reducing drag are prevalent using conceptual design.

Automobile Modeling Research Based on Numerical Simulation

2015 ◽  
Vol 733 ◽  
pp. 587-590
Author(s):  
Jie Chen ◽  
Miao Hua Huang
Keyword(s):  
Fluid Dynamics ◽  
Numerical Simulations ◽  
Vehicle Dynamics ◽  
Field Data ◽  
Aerodynamic Drag ◽  
Design Method ◽  
Aerodynamic Coefficients ◽  
Automobile Design ◽  
Air Vehicle ◽  
Computational Fluid Dynamics Cfd

In order to adapt to new modern car styling, the aerodynamic numerical simulations based on computational fluid dynamics (CFD) are applied to the process of car styling. We received the early modeling design automobile aerodynamic coefficients, pressure distribution, velocity contours and other body outflow field data after the CFD post, combined with these data some advice to improve the aerodynamic drag of the designed car are given. Proposed aerodynamic automobile design method is based on numerical simulations, according to experience in air vehicle dynamics studies.

Liver Radioembolization: An Analysis of Parameters that Influence the Catheter-Based Particle-Delivery via CFD

2020 ◽  
Vol 27 (10) ◽  
pp. 1600-1615 ◽  
Author(s):  
Jorge Aramburu ◽  
Raúl Antón ◽  
Alejandro Rivas ◽  
Juan C. Ramos ◽  
Bruno Sangro ◽  
...  
Keyword(s):  
Numerical Simulations ◽  
Particle Distribution ◽  
Numerical Approach ◽  
Radioactive Microspheres ◽  
Tumor Bearing ◽  
Hemodynamic Pattern ◽  
Valuable Treatment ◽  
Catheter Tip ◽  
Radiation Induced ◽  
Computational Fluid Dynamics Cfd

Radioembolization (RE) is a valuable treatment for liver cancer. It consists of administering radioactive microspheres by an intra-arterially placed catheter with the aim of lodging these microspheres, which are driven by the bloodstream, in the tumoral bed. Even though it is a safe treatment, some radiation-induced complications may arise. In trying to detect or solve the possible incidences that cause nontarget irradiation, simulating the particle- hemodynamics in hepatic arteries during RE by computational fluid dynamics (CFD) tools has become a valuable approach. This paper reviews the parameters that influence the outcome of RE and that have been studied via numerical simulations. In this numerical approach, the outcome of RE is regarded as successful if particles reach the artery branches that feed tumor-bearing liver segments. Up to 10 parameters have been reviewed. The variation of each parameter actually alters the hemodynamic pattern in the vicinities of the catheter tip and locally alters the incorporation of the particles into the bloodstream. Therefore, in general, the local influences of these parameters should result in global differences in terms of particle distribution in the hepatic artery branches. However, it has been observed that under some (qualitatively described) appropriate conditions where particles align with blood streamlines, the local influence resulting from a variation of a given parameter vanishes and no global differences are observed. Furthermore, the increasing number of CFD studies on RE suggests that numerical simulations have become an invaluable research tool in the study of RE.

scholarly journals CFD Simulation of a Hyperloop Capsule Inside a Low-Pressure Environment Using an Aerodynamic Compressor as Propulsion and Drag Reduction Method

2021 ◽  
Vol 11 (9) ◽  
pp. 3934
Author(s):  
Federico Lluesma-Rodríguez ◽  
Temoatzin González ◽  
Sergio Hoyas
Keyword(s):  
Shock Waves ◽  
Power Consumption ◽  
High Speed ◽  
Cfd Simulation ◽  
Aerodynamic Drag ◽  
Flow Behavior ◽  
Critical Conditions ◽  
Vehicle Speed ◽  
Blockage Ratio ◽  
The Cost

One of the most restrictive conditions in ground transportation at high speeds is aerodynamic drag. This is even more problematic when running inside a tunnel, where compressible phenomena such as wave propagation, shock waves, or flow blocking can happen. Considering Evacuated-Tube Trains (ETTs) or hyperloops, these effects appear during the whole route, as they always operate in a closed environment. Then, one of the concerns is the size of the tunnel, as it directly affects the cost of the infrastructure. When the tube size decreases with a constant section of the vehicle, the power consumption increases exponentially, as the Kantrowitz limit is surpassed. This can be mitigated when adding a compressor to the vehicle as a means of propulsion. The turbomachinery increases the pressure of part of the air faced by the vehicle, thus delaying the critical conditions on surrounding flow. With tunnels using a blockage ratio of 0.5 or higher, the reported reduction in the power consumption is 70%. Additionally, the induced pressure in front of the capsule became a negligible effect. The analysis of the flow shows that the compressor can remove the shock waves downstream and thus allows operation above the Kantrowitz limit. Actually, for a vehicle speed of 700 km/h, the case without a compressor reaches critical conditions at a blockage ratio of 0.18, which is a tunnel even smaller than those used for High-Speed Rails (0.23). When aerodynamic propulsion is used, sonic Mach numbers are reached above a blockage ratio of 0.5. A direct effect is that cases with turbomachinery can operate in tunnels with blockage ratios even 2.8 times higher than the non-compressor cases, enabling a considerable reduction in the size of the tunnel without affecting the performance. This work, after conducting bibliographic research, presents the geometry, mesh, and setup. Later, results for the flow without compressor are shown. Finally, it is discussed how the addition of the compressor improves the flow behavior and power consumption of the case.

scholarly journals Economic Development Based on a Mathematical Model: An Optimal Solution Method for the Fuel Supply of International Road Transport Activity

Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2963
Author(s):  
Melinda Timea Fülöp ◽  
Miklós Gubán ◽  
György Kovács ◽  
Mihály Avornicului
Keyword(s):  
Decision Making ◽  
Ad Hoc ◽  
Market Competition ◽  
Optimal Solution ◽  
Cost Savings ◽  
Cost Effective ◽  
Optimization Method ◽  
Optimal Decision ◽  
Environmental Damage ◽  
Fuel Cost

Due to globalization and increased market competition, forwarding companies must focus on the optimization of their international transport activities and on cost reduction. The minimization of the amount and cost of fuel results in increased competition and profitability of the companies as well as the reduction of environmental damage. Nowadays, these aspects are particularly important. This research aims to develop a new optimization method for road freight transport costs in order to reduce the fuel costs and determine optimal fueling stations and to calculate the optimal quantity of fuel to refill. The mathematical method developed in this research has two phases. In the first phase the optimal, most cost-effective fuel station is determined based on the potential fuel stations. The specific fuel prices differ per fuel station, and the stations are located at different distances from the main transport way. The method developed in this study supports drivers’ decision-making regarding whether to refuel at a farther but cheaper fuel station or at a nearer but more expensive fuel station based on the more economical choice. Thereafter, it is necessary to determine the optimal fuel volume, i.e., the exact volume required including a safe amount to cover stochastic incidents (e.g., road closures). This aspect of the optimization method supports drivers’ optimal decision-making regarding optimal fuel stations and how much fuel to obtain in order to reduce the fuel cost. Therefore, the application of this new method instead of the recently applied ad-hoc individual decision-making of the drivers results in significant fuel cost savings. A case study confirmed the efficiency of the proposed method.

Commercial CFD Code Validation for Simulation of Heavy-Vehicle External Aerodynamics

2003 ◽  
Author(s):  
W. David Pointer ◽  
Tanju Sofu ◽  
David Weber
Keyword(s):  
Aerodynamic Drag ◽  
National Laboratory ◽  
Argonne National Laboratory ◽  
Department Of Energy ◽  
Force Balance ◽  
Heavy Vehicles ◽  
Safety And Health ◽  
Energy Economy ◽  
Computational Fluid Dynamics Cfd ◽  
Vehicle Technologies

The issue of energy economy in transportation has grown beyond traditional concerns over environment, safety and health to include new concerns over national and international security. In collaboration with the U.S. Department of Energy Office of FreedomCAR and Vehicle Technologies’ Working Group on Aerodynamic Drag of Heavy Vehicles, Argonne National Laboratory is investigating the accuracy of aerodynamic drag predictions from commercial Computational Fluid Dynamics (CFD) Software. In this validation study, computational predictions from two commercial CFD codes, Star-CD [1] and PowerFLOW [2], will be compared with detailed velocity, pressure and force balance data from experiments completed in the 7 ft. by 10 ft. wind tunnel at NASA Ames [3, 4] using a Generic Conventional Model (GCM) that is representative of typical current-generation tractor-trailer geometries.

scholarly journals A 3-State Analysis of Black–White Disparities in Diabetes Hospitalizations Among Medicaid Beneficiaries

2018 ◽  
Vol 5 ◽  
pp. 233339281878351
Author(s):  
William N. Mkanta ◽  
Michelle C. Reece ◽  
Abeer D. Alamri ◽  
Emmanuel U. Ezekekwu ◽  
Aishwarya Potluri ◽  
...  
Keyword(s):  
Primary Care ◽  
Racial Differences ◽  
Self Care ◽  
Cost Savings ◽  
Cross Sectional Study ◽  
Process Of Care ◽  
Cross Sectional ◽  
Lower Odds ◽  
Logistic Regression Models ◽  
Medicaid Beneficiaries

Introduction: Although diabetes is one of the leading chronic disease in the country, efforts in primary care and patient self-care management could prevent most of the diabetes-related hospitalizations and produce cost savings and improvements in quality of life. We used information from Medicaid beneficiaries in 3 states to predict racial differences in diabetes hospitalizations and demonstrate how they vary across states. Methods: We conducted a cross-sectional study to examine differences between black and white patients with diabetes hospitalizations. Information was obtained from the Medicaid Analytic eXtract files. We used multiple logistic regression models to assess the significance of the differences. Results: Analysis included 10 073 adult Medicaid recipients from the states of Mississippi (51%), Georgia (35%), and Michigan (14%). Blacks were more likely to experience longer hospital stays in Georgia (odds ratio [OR] = 1.040; 95% confidence interval [CI]: 1.03-1.06) and Mississippi (OR = 1.048; 95% CI: 1.03-1.07). A majority of patients in both groups were likely to be discharged to their homes for self-care. Black patients had lower odds of repeated stays in Georgia (OR = 0.670; 95% CI: 0.54-0.84), but higher odds in Michigan (OR = 1.580; 95% CI: 1.12-2.24). Similar differences occurred when patients were matched by age and sex. Blacks had lower odds of qualifying for dual Medicare–Medicaid enrollment benefit in Georgia and Mississippi. Conclusion: Racial differences in diabetes-related hospitalizations reflect possible inefficiencies in the process of care. Identification of race-specific factors for hospitalizations and implementation of primary care strategies that support effective self-management skills would aid in reducing diabetes hospitalizations and related disparities.

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