scholarly journals Drag Reduction on car side mirrors with the implementation of camera modules

2021 ◽  
Author(s):  
Mahmud Hasan ◽  
Jeffrey Yokota
Keyword(s):  
Solid State ◽  
Drag Reduction ◽  
Cfd Simulation ◽  
Aerodynamic Drag ◽  
The Other ◽  
Aerodynamic Forces ◽  
Fuel Prices ◽  
Entire Vehicle ◽  
Maximum Decrease ◽  
Total Vehicle

The greatest obstacle in the acceleration of a car through air is aerodynamic drag. With this increased drag is the expenditure of fuel. About 50-60% of a vehicles’ total fuel energy is lost to overcome adverse aerodynamic forces. However, with the increase of fuel prices, many solutions have surfaced. One of these solutions are the implementation of camera modules to replace bulky traditional side mirrors. For this report, a thorough analysis was conducted into the aerodynamic benefits of these newly proposed camera modules in comparison to the conventional solid state mirrors. Specifically, one conventional side mirror along with two newly proposed camera module’s were studied in this thesis report. For this analysis, the overall drag of each module was found using CFD simulation under turbulent conditions at 60 km/h using the Realized K- method. The drag and Cd values found for the conventional side mirror were 3.985 N and 0.38 respectively. The values found for the two camera modules, Models B and C, were 0.526 N and 0.857 N. Their Cd values were found to be 0.312 and 0.365. This shows a potential of the drag reduction of the side mirror by almost 87% if the switch was made to the newer technology. This value also agreed with the prediction by Honda on their technology which has stated a possible drag reduction for this part by up to 90%. However, when observing the bigger picture, it became evident that although this drag reduction is significant for locally, it simply is not enough to make a big impact on the drag reduction of the entire vehicle. With a maximum decrease in the total vehicle drag found to to be only 4%, the reduction in the fuel consumption of the vehicle would only decrease by 0.2 gallons per mile. On the other hand, improvements in parts such as the car rims or the underbelly of the car can result in fuel improvements of upwards of 12%-25%. For this reason, it can be concluded that automobile manufacturers research other possible solutions to reduce the vehicle drag such as with the redesign of the underbelly of the car or wheel arches and rims.

scholarly journals Drag Reduction on car side mirrors with the implementation of camera modules

2021 ◽  
Author(s):  
Mahmud Hasan ◽  
Jeffrey Yokota
Keyword(s):  
Solid State ◽  
Drag Reduction ◽  
Cfd Simulation ◽  
Aerodynamic Drag ◽  
The Other ◽  
Aerodynamic Forces ◽  
Fuel Prices ◽  
Entire Vehicle ◽  
Maximum Decrease ◽  
Total Vehicle

The greatest obstacle in the acceleration of a car through air is aerodynamic drag. With this increased drag is the expenditure of fuel. About 50-60% of a vehicles’ total fuel energy is lost to overcome adverse aerodynamic forces. However, with the increase of fuel prices, many solutions have surfaced. One of these solutions are the implementation of camera modules to replace bulky traditional side mirrors. For this report, a thorough analysis was conducted into the aerodynamic benefits of these newly proposed camera modules in comparison to the conventional solid state mirrors. Specifically, one conventional side mirror along with two newly proposed camera module’s were studied in this thesis report. For this analysis, the overall drag of each module was found using CFD simulation under turbulent conditions at 60 km/h using the Realized K- method. The drag and Cd values found for the conventional side mirror were 3.985 N and 0.38 respectively. The values found for the two camera modules, Models B and C, were 0.526 N and 0.857 N. Their Cd values were found to be 0.312 and 0.365. This shows a potential of the drag reduction of the side mirror by almost 87% if the switch was made to the newer technology. This value also agreed with the prediction by Honda on their technology which has stated a possible drag reduction for this part by up to 90%. However, when observing the bigger picture, it became evident that although this drag reduction is significant for locally, it simply is not enough to make a big impact on the drag reduction of the entire vehicle. With a maximum decrease in the total vehicle drag found to to be only 4%, the reduction in the fuel consumption of the vehicle would only decrease by 0.2 gallons per mile. On the other hand, improvements in parts such as the car rims or the underbelly of the car can result in fuel improvements of upwards of 12%-25%. For this reason, it can be concluded that automobile manufacturers research other possible solutions to reduce the vehicle drag such as with the redesign of the underbelly of the car or wheel arches and rims.

Aerodynamic Forces on a Simplified Car Body: Towards Innovative Designs for Car Drag Reduction

2010 ◽  
Author(s):  
Mahmoud Khaled ◽  
Fabien Harambat ◽  
Anthony Yammine ◽  
Hassan Peerhossaini
Keyword(s):  
Drag Reduction ◽  
Drag Coefficient ◽  
Aerodynamic Drag ◽  
Cooling System ◽  
Aerodynamic Force ◽  
Lift Coefficient ◽  
Force Measurements ◽  
Vehicle Model ◽  
Aerodynamic Forces ◽  
Aerodynamic Drag Reduction

The present paper exposes the study of the cooling system circulation effect on the external aerodynamic forces. We report here aerodynamic force measurements carried out on a simplified vehicle model in wind tunnel. Tests are performed for different airflow configurations in order to detect the parameters that can affect the aerodynamic torsor and to confirm others previously suspected, especially the air inlets localization, the air outlet distributions and the underhood geometry. The simplified model has flat and flexible air inlets and several types of air outlet, and includes in its body a real cooling system and a simplified engine block that can move in the longitudinal and lateral directions. The results of this research are generic and can be applied to any new car design. Results show configurations in which, with respect to the most commonly adopted underhood geometries, the overall drag coefficient can be decreased by 2%, the aerodynamic cooling drag coefficient by more than 50% and the lift coefficient by 5%. Finally, new designs of aerodynamic drag reduction, based on the combined effects of the different investigated parameters, are proposed.

scholarly journals Understanding the Aerodynamic Benefits of Drafting in the Wake of Cyclists

Proceedings ◽  
2020 ◽  
Vol 49 (1) ◽  
pp. 32
Author(s):  
Christopher Brown ◽  
Timothy Crouch ◽  
David Burton ◽  
Mark C. Thompson
Keyword(s):  
Drag Reduction ◽  
Large Scale ◽  
Aerodynamic Drag ◽  
Dynamic Pressure ◽  
The Other ◽  
Near Wake ◽  
Reasonable Estimate ◽  
New Approach ◽  
Vortical Structures ◽  
Aerodynamic Drag Reduction

A new approach is presented to characterize the aerodynamic benefit from riding in the wake of another cyclist at different downstream locations. The method presented uses the dynamic pressure deficit in the wake of a cycling mannequin to estimate percentage drag savings. In the experiments, the time-averaged velocity behind a cycling mannequin was recorded in 1 × 0.95 m cross-planes by two four-hole pressure (Cobra) probes for four static leg positions (0°, 90°, 180°, and 270°). It was found that the wake of the cycling mannequin propagated to one side or the other as it developed downstream, depending on the strength of the two large-scale counter-rotating streamwise vortical structures shed off the hips of the mannequin. In the near wake, the complex wake dynamics resulted in an inaccurate prediction of the relative drag reduction based upon a dynamic pressure deficit. However, as the wake developed and stabilised further downstream, the dynamic pressure deficit was found to provide a reasonable estimate of the aerodynamic drag reduction of riding in the wake of the lead rider.

scholarly journals Aerodynamic Analysis of Rear Diffusers for a Passenger Car Using CFD

2020 ◽  
Author(s):  
Bugra Alkan
Keyword(s):  
Drag Reduction ◽  
Driving Forces ◽  
Aerodynamic Drag ◽  
Aerodynamic Characteristics ◽  
Cfd Simulations ◽  
Fuel Prices ◽  
Computational Fluid Dynamics Cfd ◽  
Reduction Effect ◽  
Cost Efficient ◽  
Conventional Device

Increasing environmental pollution and fuel prices are the driving forces for automotive manufacturers to develop energy efficient vehicles with lower emissions. Improving the aerodynamic characteristics and reducing the aerodynamic drag resistance of a car is the easiest and cost efficient way to handle this problem. A conventional device to improve the aerodynamics that is used on sports and racing cars is a diffuser which improve the pressure recovery on the underbody. In this study, the drag reduction effect of a diffuser has been studied on a sedan car. To understand the effects of the diffuser, computational fluid dynamics (CFD) simulations has been performed. In these simulations, diffusers with different angles were simulated to find most effective drag reduction configuration. Analyses have shown that, it is possible to improve the aerodynamic characteristics by implementing diffusers at the vehicle’s underbody.

Investigation on Aerodynamic Drag Reduction of Commercial Truck Based on External Styling of Cab

2013 ◽  
Vol 307 ◽  
pp. 186-191 ◽  
Author(s):  
Peng Guo ◽  
Xing Jun Hu ◽  
Yun Yun Zhu ◽  
Qiang Fu ◽  
Xin Yu Wang ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Wind Tunnel ◽  
Drag Reduction ◽  
Energy Saving ◽  
High Speed ◽  
Cfd Simulation ◽  
Aerodynamic Drag ◽  
Impact Mechanism ◽  
Aerodynamic Drag Reduction ◽  
The Impact

Aerodynamic drag reduction of commercial truck at high speed is one of the important ways to reduce its energy consumption. CFD simulation and wind tunnel tests are performed on a kind of commercial truck, to study the influence of the cab shape and different kinds of guide cowls on aerodynamic drag, and the impact mechanism was also analyzed. It shows that the cab shape will make great contributions to the aerodynamic drag while the truck travelling, and through improving the shape of cab, guiding the air flow passed, it can effectively reduce the aerodynamic drag and achieve energy saving.

scholarly journals Aerodynamic Shape Optimization Method of Non-Smooth Surfaces for Aerodynamic Drag Reduction on a Minivan

Fluids ◽  
2021 ◽  
Vol 6 (10) ◽  
pp. 365
Author(s):  
Zhendong Yang ◽  
Yifeng Jin ◽  
Zhengqi Gu
Keyword(s):  
Drag Reduction ◽  
Cfd Simulation ◽  
Aerodynamic Drag ◽  
Wind Tunnel Test ◽  
Flow Characteristics ◽  
Kriging Model ◽  
Optimization Method ◽  
Smooth Surfaces ◽  
Friction Resistance ◽  
Aerodynamic Drag Coefficient

To reduce aerodynamic drag of a minivan, non-smooth surfaces are applied to the minivan’s roof panel design. A steady computational fluid dynamics (CFD) method is used to investigate the aerodynamic drag characteristics. The accuracy of the numerical method is validated by wind tunnel test. The drag reduction effects of rectangle, rhombus and arithmetic progression arrangement for circular concaves are investigated numerically, and then the aerodynamic drag coefficient of the rectangle arrangement with a better drag reduction effect is chosen as the optimization objective. Three parameters, that is, the diameter D of the circular concave, the width W and the longitudinal distance L among the circular concaves, are selected as design variables. A 20-level design of an experimental study using a Latin Hypercube scheme is conducted. The responses of 20 groups of sample points are obtained by CFD simulation, based on which a Kriging model is chosen to create the surrogate-model. The multi-island genetic algorithm is employed to find the optimum solution. The result shows that maximum drag reduction effects up to 7.71% can be achieved with a rectangle circular concaves arrangement. The reduction mechanism of the roof with the circular concaves was discussed. The circular concaves decrease friction resistance of the roof and change the flow characteristics of the recirculation area in the wake of the minivan. The roof with the circular concaves reduces the differential pressure drag of the front and rear of the minivan.

A Study of an Active Rear Diffuser Device for Aerodynamic Drag Reduction of Automobiles

2012 ◽  
Author(s):  
Seung-On Kang ◽  
Jun-Ho Cho ◽  
Sang-Ook Jun ◽  
Hoon-Il Park ◽  
Ki-Sun Song ◽  
...  
Keyword(s):  
Drag Reduction ◽  
Aerodynamic Drag ◽  
Aerodynamic Drag Reduction

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 Na3Co2(As0.52P0.48)O4(As0.95P0.05)2O7

2013 ◽  
Vol 69 (12) ◽  
pp. i85-i86 ◽  
Author(s):  
Youssef Ben Smida ◽  
Abderrahmen Guesmi ◽  
Mohamed Faouzi Zid ◽  
Ahmed Driss
Keyword(s):  
Solid State ◽  
Solid State Reaction ◽  
Title Compound ◽  
General Position ◽  
Structural Model ◽  
Three Dimensional ◽  
The Other ◽  
Coordination Polyhedra ◽  
Bond Valence Sum ◽  
Full Occupancy

The title compound, trisodium dicobalt(II) (arsenate/phosphate) (diarsenate/diphosphate), was prepared by a solid-state reaction. It is isostructural with Na3Co2AsO4As2O7. The framework shows the presence of CoX22O12(X2 is statistically disordered with As0.95P0.05) units formed by sharing corners between Co1O6octahedra andX22O7groups. These units form layers perpendicular to [010]. Co2O6octahedra andX1O4(X1 = As0.54P0.46) tetrahedra form Co2X1O8chains parallel to [001]. Cohesion between layers and chains is ensured by theX22O7groups, giving rise to a three-dimensional framework with broad tunnels, running along thea- andc-axis directions, in which the Na+ions reside. The two Co2+cations, theX1 site and three of the seven O atoms lie on special positions, with site symmetries 2 andmfor the Co,mfor theX1, and 2 andm(× 2) for the O sites. One of two Na atoms is disordered over three special positions [occupancy ratios 0.877 (10):0.110 (13):0.066 (9)] and the other is in a general position with full occupancy. A comparison between structures such as K2CdP2O7, α-NaTiP2O7and K2MoO2P2O7is made. The proposed structural model is supported by charge-distribution (CHARDI) analysis and bond-valence-sum (BVS) calculations. The distortion of the coordination polyhedra is analyzed by means of the effective coordination number.

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