Browse Topic: Air deflectors

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Aerodynamic Analysis of Heavy-Duty Vehicles Using Computational Fluid Dynamics Approach2022-28-049212/23/2022
Fuel consumption of heavy-duty vehicles (HDV) is one of the major challenges in the automotive industry. In recent days, gasoline prices have been raised high, so the HDVs need to be designed to be more fuel-efficient. Many studies reported that aerodynamic optimization is one of the most important advancements in terms of fuel-efficient HDVs. The computational fluid dynamics (CFD) tool or approach is widely accepted for aerodynamic analysis. This study identifies the flow zones with the large pressure drag and design parameters, incorporating appropriate geometric changes into the design. The computational results show that the drag reduction of individual devices in cab and trailer is 15.9%. The cab deflector and boat tails are the most effective individual geometry and successfully reduce the drag up to 20
Sajjala, Sai Mukesh Reddy, Shaik, Mahaboob Subhani
Technical Paper
Numerical Characterization of Brake System Cooling, Aerodynamic, and Particle Soiling Performances under Driving Conditions2020-01-162210/05/2020
Effective cooling of a heated brake system is critical for vehicle safety and reliability. While some flow devices can redirect airflow more favorably for convective cooling, such a change typically accompanies side effects, such as increased aerodynamic drag and inferior control of brake dust particles. The former is critical for fuel efficiency while the latter for vehicle’s soiling and corrosion as well as non-exhaust emissions. These competing objectives are assessed in this study based on the numerical simulations of an installed brake system under driving conditions. The thermal behavior of the brake system as well as aerodynamic impact and brake dust particle deposition on areas of interest are solved using a coupled 3D transient flow solver, PowerFLOW. Typical design considerations related to enhanced brake cooling, such as cooling duct, wheel deflector, and brake air deflector, are characterized to evaluate the thermal, aerodynamic and soiling performance targets. The leading
Cho, Young-Chang, Jilesen, Jonathan, Kandasamy, Satheesh
Journal Article
Innovative Rear Air Blower Design Application for Improving Cabin Thermal Comfort with Improved Air Distribution and Air Quality2020-28-003408/18/2020
In recent times, overall thermal comfort and air quality requirement have increased for vehicle cabin by multifold. To achieve increased thermal comfort requirements, multiple design innovation has happened to improve HVAC performance. Most of the advance features like multizone HVAC, dedicated rear HVAC, Automatic climate control, advance air filters, and ionizers etc. lead to increase in cost, power consumption, weight, and integration issues. Besides this in the vehicle with only front HVAC, airflow is not enough to meet rear side comfort for many cars in the B/C/SUV segment. This study aims to analyze the various parameters responsible for human thermal comfort inside a car. The focus of study is to use light weight, low power consumption, compact Rear Blower to provide passengers comfort by providing optimum airflow inline of mean radiant temperatures and cabin air temperature. The rear blower incorporates external surfaces with a set of air modifier in the direction of flow
Garg, Ravi, maske, Suraj, Kushwah, Yogendra Singh
Technical Paper
Aeroelastic Response and Structural Improvement for Heavy-Duty Truck Cab Deflectors2019-01-500401/14/2019
Numerical simulations on the fluid-structure interaction were conducted using commercial software STAR-CCM+ and ABAQUS. The aeroelastic responses of a deflector under several different working conditions were simulated utilizing finite volume and finite element methods to investigate the aeroelastic problem of automotive deflectors. Results showed that the structural response of a top deflector is minimal under the influence of aerodynamics given its large structural stiffness. The size of the top deflector was optimised by using thickness as a variable. The volume and quality of the top deflector were significantly reduced, and its lightweight performance was improved to satisfy the stiffness performance requirement. The vibration of a side deflector structure was mainly induced by the turbulence on the structure surface. The amplitude of vibration was small and the vibration gradually converged in a few seconds without obvious regularity. Six structures were constructed to reduce the
Wang, Jing-yu, Yan, Wei, Sang, Tao, Guo, Peng, Wu, Bin, Zhang, Jing-long, Hu, Xingjun, Dong, Chun-bo
Technical Paper
Method for Preventing Contamination on Trucks Cabin Side Using CFD2017-36-008011/07/2017
Although ignored by most people not directly involved with highway and off-road commercial trucks operation the accumulation of dust and mud on cabin side can become a rather annoying issue. Besides adhering to the passengers clothes dirt contamination may also compromise driver visibility constituting a safety concern. For a truck manufacturer it can revert into quality complaints and negatively influence customers’ future buying decisions. In this context, fascia air deflectors are common devices used in truck industry to control the airflow over the cabin panels and ultimately prevent contamination deposition. This paper presents a methodology to avoid dust and mud accumulation on commercial trucks cabin doors based on the predicted airflow field by computational fluid dynamics (CFD) and a reference flow metric defined through a simple bench test. Comparing the results of the CFD analysis with an experimental study it is demonstrated that without resorting to costly wind tunnel
Costa, Edinilson Alves, Nalin, Rogério
Technical Paper
Glowing aerodynamic add-ons could boost big-rig fuel economy by 7-1017TOFHP02_0702/01/2017
“Headlight white” and “stoplight red,” the characteristic colors of the highway at night, could soon get a companion: “plasma purple”-that is, if a new fuel-saving, aerodynamic technology catches on big with big-rig trucks. The electric plasmas emitted by the devices, which glow purple-violet in the dark, can smooth the turbulent wakes that sweep off the rear edges of truck trailers travelling at highway speeds. Simulations and wind tunnel tests indicate that these novel active-flow control systems could reduce the aerodynamic drag generated by semi-trailers by almost one-fifth, thus lowering fuel consumption by up to 10%. Plasmas, the lesser-known “fourth state of matter,” are clouds of charged atomic ions created in the air by high-voltage electric fields. The glowing electric-flame phenomena are commonly seen in household air purifiers and more rarely in natural phenomena such as St. Elmo's Fire, the ghostly purple haze sometimes seen hanging off airplane wings. For application to
Ashley, Steven
Magazine Article
2017 Nissan Titan gets new platform, powertrain, cab and bed features16AUTP10_1210/01/2016
The second-generation Nissan Titan launches with the model's first-ever single cab and adds a direct-injection V8 and 7-speed transmission plus significantly improved vehicle aerodynamics and NVH attenuation. And while the 2017 model does not achieve a net mass reduction versus the previous Titan, fuel efficiency has been improved 28%, engineers claim. The new Titan also brings a cool new approach to cargo bed illumination and claims an industry first: the first full-size pickup with a 5-year/100,000 mile bumper-to-bumper warranty. There's also a V6 engine in the development pipeline
Buchholz, Kami
Magazine Article
Analysis of Aerodynamic Performance of a High Energy Efficiency Prototype2012-36-031810/02/2012
This paper presents a study developed in order to improve the aerodynamic performance of an automotive prototype by means of simulations carried out by a software that makes of the finite volume method. The prototype will be built at the Laboratory of Automotive Engineering of the Lutheran University of Brazil - ULBRA. Taking into account the original design of the automotive prototype, three virtual models were generated and analyzed. There were three steps to simulate the aerodynamic behavior on a 3D model: generation of the geometry with the employment of CAD software, generation of the mesh for the faces and volume that involve the car, using specific software, and solving the flow, with a CFD software. The results of the analysis allowed identifying the model with the lowest aerodynamic drag. That model had some modifications on its design, when compared to the original one, like wheels and their housings. Also, an air deflector was included on the back of the virtual prototype
Rodrigues, Antonio Flavio Aires, Gertz, Luiz Carlos, Cervieri, Andre, Da Silveira, Marilia Amaral, Da Silva, Tiago Portolon
Technical Paper
Aerodynamics soarAUTOSEP09_0409/01/2009
Automakers toil to minimize drag and maximize fuel economy. Decades ago, it was conventional wisdom that by now we would all be driving slippery, low-slung, low-drag transportation modules optimized for efficient consumption of limited resources. All the futuristic movies said it was so. Triumph-apparently unaware that the future would not include that marque-touted the wedgy TR7 as “The Shape of Things to Come.” And so it seemed it would be, with the popularization of the sleek Ford Taurus family sedan in the mid-′80s. But then came a couple decades of cheap gasoline, the SUV boom, and the defiantly blunt Chrysler 300 sedan, and the notion of designing for drag reduction seemed to have been swept away in an eddy current of a Hummer's wake
Carney, Dan
Magazine Article
Development of a Cost Effective Power Train Cooling System for a Passenger Car with Rear Engine2009-01-016904/20/2009
The present automobile era in India is driven by development of small size and low cost ‘value for money’ cars. Proper utilization of space and low cost engineering of the vehicle aggregates plays a key role for attaining the goal of low cost-small cars. This paper illustrates the development of power train cooling system of such cost sensitive passenger car with rear engine and rear mounted heat exchangers. The major obstacle for the power train cooling system of rear engine-rear mounted heat exchanger (radiator) is absence of ram air effect at higher vehicle speeds and air temperatures higher then ambient, as observed for front mounted heat exchanger. The subject vehicle encountered power train cooling system failure at max speed operating condition and the project timeline required a quick solution without any major modifications and cost escalation. In case of subject vehicle because of its packaging, the air flow rate for heat exchanger was fully dependent of fan capacity. However
T, Rajesh A, Pol, Sharad
Technical Paper
CFD Application in Automotive Front-End Design2006-01-033704/03/2006
The front-end design process in the automotive industry today is time consuming and expensive. Although CFD (Computational Fluid Dynamics) modeling is helpful, many vehicle development tests in different wind tunnels are still required to balance the competing requirements of power train cooling, vehicle aerodynamics, climate control, styling, body structure, and product cost. For example, engine cooling and climate control heat exchangers require adequate airflow to achieve their performance. But, this airflow increases cooling drag and can compromise vehicle handling. Internal air deflectors (ducting) are often used to make the frontal opening more efficient and help prevent heat recirculation from the hot engine compartment to the A/C condenser at idle. But this increases product cost and can compromise underhood temperature. A more efficient and faster process is needed to support these trade-off discussions. The objective of this report is to examine the suitability of using one
Ding, Wei, Williams, Jack, Karanth, Dinakara, Sovani, Sandeep
Technical Paper
Shape Study for a Low-Air Resistance Air Deflector - The Second Report95063302/01/1995
We reported, in our first report1), the study of shapes of air deflectors that have strong yawing angle characteristics for the air resistance encountered when vehicles are running at high speed, taking into account the ambient wind. However, it is rarely the case that the optimum shape of air deflector, which was obtained and reported in our first report, is directly adopted for practical use. This paper reports the results of measurement tests on how the air resistance increases (worsens) when an air deflector is mounted on the cab of a vehicle: in the case when the air deflector was slightly changed on the same vehicle; or when the parameters of the vehicle (the height of the rear body) were changed for the same air deflector. We obtained the following results: Considerations and adjustments are required not to allow flows passing over upper and side surfaces of the air deflector to hit the front surface of the rear body. Further, the fuel consumption under the above conditions was
Fujimoto, Tsutomu, Niinuma, Atsushi, Sakai, Katsuharu
Technical Paper
Shape Study for a Low Air Resistance Air Deflector93030103/01/1993
The van-type truck is frequently equipped with an air deflector to reduce fuel consumption. When studying the shape of the air deflector, it is necessary to choose a shape that is less sensitive to yaw characteristics. Side wind induced yaw conditions are more typical of on-road usage. In this study, the basic characteristics for a shape with strong yaw sensitivity were first examined. Subsequently, an angle change test was carried out by replacing the space over the cab with a rectangular parallelopiped and letting the upper and side edges, just in front of the rear body be the reference lines. The yaw angle was varied between 0°, 5°, and 10°. From this result, the existence of the optimum upper and side incident angles was confirmed. Furthermore, the reduction in fuel consumption using the optimum shape as compared with the conventional shape was estimated by simulation
Fujimoto, Tsutomu
Technical Paper
Comparison of On-Road and Wind-Tunnel Tests for Tractor-Trailer Aerodynamic Devices, and Fuel Savings Predictions85028602/01/1985
Wind tunnels which are large enough for full-scale trucks are rare, and the cost of satisfactorily-detailed models for smaller tunnels is high. The work presented shows the results from the application of a method which provides an over-the-road evaluation of the incremental changes in fuel consumption and drag coefficient produced following the addition of a variety of aerodynamic drag reducing devices to a tractor-trailer truck combination. The devices tested were an aerodynamic sunvisor, a roof-mounted air deflector, cab extenders, cab skirts, a trailer nose fairing, a set of trailer quads (quarter-rounds), and trailer skirts which were mounted on a low-forward-entry tractor and high box-van trailer. The significant differences between the wind tunnel and on-road drag reductions suggest that the effects of on-road wind turbulence can substantially reduce the wind tunnel results even though a 1.5% turbulence intensity level was used in the tunnel experiments. These experiments have
Saunders, Jeffrey W., Watkins, Simon, Hoffmann, Peter H., Buckley, Frank T.
Technical Paper
TOWABILITY DESIGN CRITERIA—PASSENGER CARS AND LIGHT DUTY TRUCKSJ1142A_197806 (Historical)06/01/1978
Towability Committee
Recommended Practice
TOWABILITY DESIGN CRITERIA—PASSENGER CARSJ1142_197607 (Historical)07/01/1976
Towability Committee
Recommended Practice
Development of the First Sheet Molding Compound (SMC) Body Component: The Chrysler Station Wagon Air Deflector72049302/01/1972
The Chrysler Corporation made use of a thermosetting polyester sheet-molding-compound (SMC) to provide an efficient, neat-appearing, and economical station wagon air deflector for its 1969 full-size station wagons. This marked Chrysler's first usage of this material for a major automotive body component
Currier, George J.
Technical Paper
HIGH OPERATING-TEMPERATURE AND ENGINE AND CAR OPERATION26001601/01/1926
This subject is treated in a paper in two parts. Part I, by Alex Taub, deals with laboratory tests to prove by comparative data that the higher average operating-temperatures maintained in the engine by the constant-temperature, or evaporation, system of cooling have negligible detrimental effects. Part II, by L. P. Saunders, gives the results of road-tests of cars operated under the same conditions when fitted with a standard water-cooling radiator-core and with a constant-temperature cross-flow condenser-core. Although contamination of the crankcase oil by heavy ends of the fuel is not prevented by the higher temperature of constant-temperature operation, it is asserted that this higher temperature is effective in striking an acceptable balance in such contamination and results of the tests show that the cylinder-walls are maintained at temperatures sufficiently above the vaporization point of water to reduce the condensation of water vapor to the minimum. Water in the crankcase is
Technical Paper
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