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Viewing 1 to 30 of 2522
2015-06-25
Event
This session is to present numerical and experimental work pertaining to noise due to flow around the vehicle body, such as flow-induced interior noise, flow over protrusions, sunroofs, windows, noise from ventilation systems, or flow noise in exhaust system. Papers on aerodynamics alone without sound are excluded. Numerical studies may include new models or models based on existing theory as long as they are adequately supported by experimental or theoretical verifications.
2015-06-24
Event
This session is to present numerical and experimental work pertaining to noise due to flow around the vehicle body, such as flow-induced interior noise, flow over protrusions, sunroofs, windows, noise from ventilation systems, or flow noise in exhaust system. Papers on aerodynamics alone without sound are excluded. Numerical studies may include new models or models based on existing theory as long as they are adequately supported by experimental or theoretical verifications.
2015-06-24
Event
This session is to present numerical and experimental work pertaining to noise due to flow around the vehicle body, such as flow-induced interior noise, flow over protrusions, sunroofs, windows, noise from ventilation systems, or flow noise in exhaust system. Papers on aerodynamics alone without sound are excluded. Numerical studies may include new models or models based on existing theory as long as they are adequately supported by experimental or theoretical verifications.
2015-06-22
Event
This session is devoted to NVH issues arising within the aeronautical and aerospace industries, such as community noise, aircraft interior noise, aerospace vibro-acoustics, noise prediction, modeling and modal analysis.
2015-04-23
Event
Vehicle aerodynamic development, drag reduction and fuel economy, handling and stability, cooling flows, surface soiling and water management, vehicle internal environment, tyre aerodynamics and modelling, aeroacoustics, structural response to aerodynamic loading, simulating the on-road environment, onset flow turbulence, unsteady aerodynamics, fundamental flow structures, new test methods and facilities, new applications of computational fluid dynamics simulation, competition vehicle aerodynamics.
2015-04-23
Event
Vehicle aerodynamic development, drag reduction and fuel economy, handling and stability, cooling flows, surface soiling and water management, vehicle internal environment, tyre aerodynamics and modelling, aeroacoustics, structural response to aerodynamic loading, simulating the on-road environment, onset flow turbulence, unsteady aerodynamics, fundamental flow structures, new test methods and facilities, new applications of computational fluid dynamics simulation, competition vehicle aerodynamics.
2015-04-22
Event
Vehicle aerodynamic development, drag reduction and fuel economy, handling and stability, cooling flows, surface soiling and water management, vehicle internal environment, tyre aerodynamics and modelling, aeroacoustics, structural response to aerodynamic loading, simulating the on-road environment, onset flow turbulence, unsteady aerodynamics, fundamental flow structures, new test methods and facilities, new applications of computational fluid dynamics simulation, competition vehicle aerodynamics.
2015-04-22
Event
Vehicle aerodynamic development, drag reduction and fuel economy, handling and stability, cooling flows, surface soiling and water management, vehicle internal environment, tyre aerodynamics and modelling, aeroacoustics, structural response to aerodynamic loading, simulating the on-road environment, onset flow turbulence, unsteady aerodynamics, fundamental flow structures, new test methods and facilities, new applications of computational fluid dynamics simulation, competition vehicle aerodynamics.
2015-04-22
Event
The purpose of this session is to bring awareness among the automotive aerodynamics, thermal and hydraulic systems development community to address the need of reliability analysis and robust design to improve the overall product quality. This session also introduces CAE based optimization of aero-thermal and fluid systems to improve automotive fuel economy. This session presents papers covering both testing and simulation.
2015-04-21
Event
Vehicle aerodynamic development, drag reduction and fuel economy, handling and stability, cooling flows, surface soiling and water management, vehicle internal environment, tyre aerodynamics and modelling, aeroacoustics, structural response to aerodynamic loading, simulating the on-road environment, onset flow turbulence, unsteady aerodynamics, fundamental flow structures, new test methods and facilities, new applications of computational fluid dynamics simulation, competition vehicle aerodynamics.
2015-04-21
Event
Vehicle aerodynamic development, drag reduction and fuel economy, handling and stability, cooling flows, surface soiling and water management, vehicle internal environment, tyre aerodynamics and modelling, aeroacoustics, structural response to aerodynamic loading, simulating the on-road environment, onset flow turbulence, unsteady aerodynamics, fundamental flow structures, new test methods and facilities, new applications of computational fluid dynamics simulation, competition vehicle aerodynamics.
2015-04-21
Event
Vehicle aerodynamic development, drag reduction and fuel economy, handling and stability, cooling flows, surface soiling and water management, vehicle internal environment, tyre aerodynamics and modelling, aeroacoustics, structural response to aerodynamic loading, simulating the on-road environment, onset flow turbulence, unsteady aerodynamics, fundamental flow structures, new test methods and facilities, new applications of computational fluid dynamics simulation, competition vehicle aerodynamics.
2015-04-14
Technical Paper
2015-01-1698
Balamurugan Rathinam, Frederic Ravet, Cedric Servant, Laurent Delahaye, Upendra Naithani
Optimising the in-cylinder aerodynamics in Spark ignition (SI) engines is one of the most important contribution to improve the combustion efficiency and thus to save the fuel consumption and to limit CO and unburnt hydrocarbon emissions. The tumble motion originated near the Top Dead Centre (TDC) known as “Tumble Squeeze” is responsible for higher level of turbulence which is necessary to increase the turbulent flame velocity. Higher the flame velocity is, higher the combustion efficiency is. Experiments are conducted in an optical engine and the velocity fields are measured with the aid of advanced particle image velocimetry (PIV) measurement technique. The velocity fields are computed through simulation and compared with measurements. Then, the turbulence kinetic energy is also calculated from the velocity fields which are basically not possible to measure from the experiments. This study is performed for three different operating points with low and high tumble configurations.
2015-04-14
Technical Paper
2015-01-1549
Jonathan Jilesen, Adrian Gaylard, Iwo Spruss, Timo Kuthada, Jochen Wiedemann
Driving when it is raining can be a stressful experience. Having a clear unobstructed view of the vehicles and road around you under these conditions is especially important. Heavy rain conditions can however overwhelm water management devices resulting in water rivulets flowing over the vehicle’s side glass. These rivulets can significantly impair the driver’s ability to see the door mirror, and laterally onto junctions. Designing water management features for vehicles is a challenging venture as testing is not normally conducted until late in the design phase. Additionally traditional water management features such as grooves and channels have both undesirable design and wind noise implications. Having the ability to detect water management issues such as A-pillar overflow earlier in the design cycle is desirable to minimize the negative impact of water management features. Numerical simulation of windscreen water management is desirable for this reason.
2015-04-14
Technical Paper
2015-01-1534
Daisuke Nakamura, Yasuyuki Onishi, Yoshiyasu Takehara
Reducing drag contributes to greater fuel efficiency and exhaust gas reduction. Regarding aerodynamic performance, every detail must be considered and resistance must be reduced. A vehicle’s package design—the vehicle's fundamental framework—must be considered. This paper introduces factors that contribute significantly to drag . The paper also discusses methods for improving aerodynamic performance. To balance exterior design with aerodynamic performance, a shape that improves aerodynamic performance must be proposed early on. We used 1/4 scale clay models to identify and analyze areas having a significant aerodynamic impact. More than 500 total variation measurements were conducted for 16 items. Based on the results of these measurements, analysis of flow-field was conducted using CFD.
2015-04-14
Technical Paper
2015-01-1535
Kentaro Machida, Munetsugu Kaneko, Atsushi Ogawa
Reduction of aerodynamic drag is important to improve fuel economy and mitigate the effects on the global environment. There are other technical issues which severely limit how far the vehicle’s shape can be changed. Reducing drag poses the challenge of efficiently extracting features of improved aerodynamic performance and deciding how to balance drag reduction with other functions, such as crash safety, field of vision, and interior comfort. Under these limitations, it is effective to analyze the flow around the vehicle by CFD (computational fluid dynamics) simulations to establish a drag reduction strategy. The Flow Analysis Simulation Tool (FAST) system performs aerodynamic simulation by linking exterior surface design with predefined platform layout. This allowed engineers to run calculations efficiently, independent of their level of experience in CFD.
2015-04-14
Technical Paper
2015-01-1533
Massimiliana Carello, Serra Andrea, Andrea Giancarlo Airale, Alessandro Ferraris
XAM is a prototype (developed at the Politecnico of Torino) of a two seat city vehicle, equipped with a hybrid propulsion system., to obtain low consumptions and reduced environmental impact. The designing process of this vehicle was carried out keeping attention to the requirements of the weight reduction and of the aerodynamic optimization of the shapes of the body, constitute the main specification considered designing XAM in order to consequently get a reduction of consumptions, while guarantying roominess and comfort. According to this, it has been designed a windscreen that makes a one-piece with the roof in order to avoid any discontinuity and consequently any loss due to whirling dissipations in the intersection area.
2015-04-14
Technical Paper
2015-01-1528
Kenichi Hirose, Rina Nakagawa, Yukitaka Ura, Hideyuki Kawamata, Hisashi Tanaka, Munehiko Oshima
The door mirrors of a vehicle are one of the significant components generating drag, due to projection from the vehicle body. The ratio of door mirror drag accounts for 2.5-5 percent of the overall aerodynamic drag of the vehicle. The drag ratio is larger than the frontal area ratio of door mirrors and vehicle body. Since it is considered that door mirror drag is composed of not only profile drag but also interference drag that is generated by the mixing of airflow streamlines between door mirrors and vehicle body. However, the generation mechanism of interference drag remained unexplained, so elucidating mechanisms for countermeasures have been needed. In this study, the prediction formulas for door mirror drag expressed by functions in relation to velocities around the vehicle body were derived and verified by wind tunnel test. Door mirror drag is defined as the difference between aerodynamic drag on a vehicle with and without mirrors.
2015-04-14
Technical Paper
2015-01-1543
Petter Ekman, Roland Gårdhagen, Torbjörn Virdung, Matts Karlsson
Road transportation by trucks is the major part of the goods transportations system in the European Union (EU). With increased fuel prices and a simultaneous demand for significantly reduced emissions there is a need for increased fuel efficiency. While truck manufacturers already spend significant resources in order to reduce the emissions from their vehicles, most truck manufacturers do not control the shape of the trailer and/or swap bodies. These devices are bodies that are usually manufactured by different, sometimes several different, manufactures that cannot consider the overall aerodynamics around the complete vehicle. It is well known that the aerodynamic resistance constitutes a significant part of the vehicles driving resistance and that four areas (front of vehicle, gap, side/underbody and rear) of the vehicle contributes about one quarter each.
2015-04-14
Technical Paper
2015-01-1542
Masaaki Arai, Keitaro Tone, Keiichi Taniguchi, Mikako Murakami, Munehiko Oshima
This paper describes the development of the aerodynamics of the new Nissan Murano. This vehicle was developed using full-scale wind tunnel testing and Computational Fluid Dynamics simulations (CFD). Three key aerodynamic features -front spoiler, active grille shutter and rear upper body were developed in particular for reducing aerodynamic drag. A large front spoiler was designed to reduce floor drag, especially drag produced by a uneven floor. The front spoiler shape was optimized by designing the lip shape to augment the separation angle of flow, thereby inhibiting the penetration of strong flow to the floor. An active grille shutter was adopted behind the front lower grille opening to reduce engine room drag substantially when engine cooling air is unnecessary. Based on a parameter study, we found that a lower grille is beneficial for the inlet for cooling. Therefore, the upper grille opening area was minimized, and conversely the lower grille opening area was maximized.
2015-04-14
Technical Paper
2015-01-1541
Kuo-Huey Chen, Bahram Khalighi
Various drag reduction strategies have been applied to a full size production pickup truck to evaluate their effectiveness by using a Computational Fluid Dynamics (CFD). The drag reduction devices evaluated in this study were placed at the rear end of the truck bed and the tailgate. Two types of devices were evaluated: (1) boat tail-like extended plates attached to the tailgate and (2) flat plates partially covering the truck bed. The effect of drag reduction by various combination of the above are presented in this paper. Twenty-four configurations were evaluated in the study with the best achievable drag reduction of around 21 counts (ΔCd=0.021). A detailed breakdown of the pressure differentials at the base of the truck is provided in order to understand the flow mechanism for the drag reduction. It is concluded that the added surfaces near the tailgate lower the static pressure on the inner side of the tailgate in addition to the pressure increase at the base.
2015-04-14
Technical Paper
2015-01-1538
Neil Ashton, Alistair Revell
Computational Fluid Dynamics (CFD) has increasingly provided the methodology behind an important design tool for the automotive industry. With a desire to reduce noise levels and improve fuel efficiency, reliable CFD simulations of the complex separated turbulent flow around vehicles is becoming an ever more crucial goal. The Ahmed car body [1] has long been one of the most popular automotive test cases because of detailed experimental data and an extensive record of previous simulations. Unfortunately whilst the Ahmed car body represents some of the key aerodynamic features of a full car (such as the vortex shedding and 3D separation), it is still a much-simplified model. A recent development to bridge this gap between models such as the Ahmed car body and a realistic full car model is the DrivAer model [2]. Together with recent experimental and numerical simulations it represents an excellent open-source full-car test case to validate and develop turbulence models.
2015-04-14
Technical Paper
2015-01-1536
Brett C. Peters, Mesbah Uddin, Jeremy Bain, Alex Curley, Maxwell Henry
Currently, most computational fluid dynamic solvers rely heavily on the robustness of unstructured finite volume discretization to solve complex flows. Finite volume solvers are restricted to second order spatial accuracy while structured finite difference codes can easily resolve up to five orders of spatial discretization and beyond. In order to solve flow around complicated geometries, unstructured finite volume codes are employed to avoid tedious and time consuming hand made structured meshes. By using overset grids and NASA's overset grid solver, OVERFLOW, structured finite difference solutions are easily achievable for complex geometries such as the DrivAer model. This allows for higher order flow structures to be captured as compared to traditional finite volume schemes. The current paper investigates flow field solutions computed with finite volume and finite difference methods for the DrivAer model.
2015-04-14
Technical Paper
2015-01-1551
Andrew D'Hooge, Luke Rebbeck, Robert Palin, Quinn Murphy, Joaquin Gargoloff, Bradley Duncan
Aerodynamic evaluation of vehicles using static yaw angle changes in wind tunnel testing and numerical simulation has been used as standard practice for evaluating vehicle performance under a range of wind conditions. However, this approach does not consider dynamic wind effects coming from changing wind conditions, passing other vehicles and roadside obstacles, and transient non-uniform wind conditions coming from environmental turbulence. In previous work by the authors, computational fluid dynamics (CFD) simulation methodology for considering dynamic wind conditions and on-road turbulence was demonstrated, showing the important effects of the wind conditions on the vehicle aerodynamics. The technique allows the vehicle to be tested under a range of transient gust conditions, also accounting for wind turbulence coming from upstream vehicles and natural environmental wind fluctuations.
2015-04-14
Technical Paper
2015-01-1550
Lars Graening, Thomas Ramsay
In many engineering domains like aerospace, vehicle or engine design the analysis of flow fields, acquired from computational fluid dynamics (CFD) simulations can reveal important insights on the behavior of the simulated objects. However, the huge amount of flow data produced by each simulation complicates the data processing and limits the application of data mining and machine learning tools for the flow analysis. The paper introduces a compact stream line and feature based representation of three dimensional flow fields, in order to overcome this limitation. The compact representation defines the basis for a subsequent quantification of flow field similarities.
2015-04-14
Technical Paper
2015-01-1545
Lennert Sterken, Simone Sebben, Lennart Lofdahl, Tim Walker, Thies Wölken
Vehicle manufacturers are constantly looking for new innovative ideas to reduce fuel consumption and CO2-emissions. The need is highlighted from tougher legislation regarding CO2 which are to be endorsed in the near-future. Aerodynamics can contribute to the topic of energy-efficient vehicles through a reduction of the aerodynamic drag. The air resistance is mainly caused by a pressure difference between the front and rear of the vehicle. Consequently, an increase in base pressure lowers the aerodynamic drag. Previous research on both small-scale and full-scale vehicles shows that base extensions are an effective method to increase the base pressure, enhancing pressure recovery and reducing the wake size. These extensions decrease drag at zero yaw, but show an even larger improvement at small yaw angles.
Viewing 1 to 30 of 2522

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