Some Salient Features Of The Time-Averaged Ground Vehicle Wake

Ahmed, Shehzad; Ramm, G.; Faltin, G.

doi:10.4271/840300

Cited by 816 publications

(701 citation statements)

References 4 publications

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“…The Ahmed car body [1][2] represents a generic car geometry with a slanted back and a flat front and has been extensively tested in the literature [20,21,22,23,24]. While it is a much simplified version of a real car, it nevertheless provides many of flow features found in real-life cars such as the complex vortex interactions that occur in its wake and the large 3D separation region behind the car body itself.…”

Section: Ahmed Car Bodymentioning

confidence: 99%

“…The test case of this paper is the one initially defined in 2001 during the 9th ERCOFTAC Workshop on Refined Turbulence Modelling [46] for a body with subcritical slant angle u = 25°at a Reynolds number of Re = 768,000 (note that in [1] the Reynolds number is based on the length of the body). Measurements were performed by Lienhart and Becker [22,23].…”

Section: Computational Grid and Boundary Conditionsmentioning

confidence: 99%

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Assessment of RANS and DES methods for realistic automotive models

et al. 2016

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Section: Ahmed Car Bodymentioning

confidence: 99%

Section: Computational Grid and Boundary Conditionsmentioning

confidence: 99%

Assessment of RANS and DES methods for realistic automotive models

et al. 2016

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“…The size of the computational domain is consistent with the previous studies (see for example, [18][19][20]), where the blockage effects are minimized. The standard dimensions for the Ahmed body with the rear slant angle  = 35 o were used, as shown in Figure 1(b), which may be found in [17,18]. Due to the complex geometry (i.e.…”

Section: Introductionmentioning

confidence: 99%

“…Therefore, in the present article, we aim to investigate the potential for exploiting the flow-induced vibrations of rear car spoilers for energy harvesting. To that end, we undertake the fluid-structure interaction (FSI) analysis of an inverted NACA 2408 rear spoiler and we employ an Ahmed body [17] with a 35 o rear slant angle in order to represent a car. An Ahmed body is a simplified generic bluff body that captures important aerodynamic features around conventional cars and has been frequently used as a reference test case in the automotive industry [18].…”

Section: Introductionmentioning

confidence: 99%

Fluid-structure interaction analysis of rear spoiler vibration for energy harvesting potential

Rasani¹,

Aldlemy

Harun³

2017

J. MECH. ENG. SCI.

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Increasing environmental and energy concerns constitutes an encouraging development of future automobiles and autonomous vehicles that utilize cleaner and renewable energy. Although primarily an aerodynamic device, car rear spoilers experience various vibrations and limited attention has been given to exploiting these vibrations for generating alternative energy. This paper aims to investigate the potential of using the flow-induced vibration of rear spoilers on automobiles for energy harvesting. To that end, a fluid-structure interaction analysis of an inverted NACA 2408 spoiler behind an Ahmed body was undertaken. An Arbitrary Lagrangian-Eulerian flow solver was coupled to a non-linear structural dynamic solver using a commercial software application. The vibrations of the rear spoiler placed at 0, 50 and 100 mm below the top face of the Ahmed body under Reynolds number Re = 2.7 × 10 6 were simulated. It was found that the vibration of the rear spoiler at the highest elevation showed the largest amplitudes and strain, but the vibration of the rear spoiler at the lowest elevation offers an extended period of vibration before reaching a steady state. With the rear spoiler positioned at the highest elevation, a vibration frequency of 70 Hz and a steady-state principal strain of 350  may be achieved. These vibration levels compared well with previous investigation to sufficiently charge storage capacitors for wireless transmitters. The rear spoiler vibration may offer potential means for energy harvesting, and warrants further experiments under actual driving conditions.

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“…The Ahmed vehicle model is a very simplified bluffbody which is frequently employed as a benchmark in vehicle aerodynamics. It has been used in several experiments [3][4][5][6][7] and numerical studies [8][9][10][11][12][13]. In another computational study, a passenger van is modeled with a modified form of Ahmed's body by changing the orientation of the flow from its original form (modified/reversed Ahmed Body).…”

Section: Introductionmentioning

confidence: 99%

Modification of Flow Structure Over a Van Model by Suction Flow Control to Reduce Aerodynamics Drag

Harinaldi¹,

Budiarso²,

Warjito³

et al. 2012

MST

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Automobile aerodynamic studies are typically undertaken to improve safety and increase fuel efficiency as well as to find new innovation in automobile technology to deal with the problem of energy crisis and global warming. Some car companies have the objective to develop control solutions that enable to reduce the aerodynamic drag of vehicle and significant modification progress is still possible by reducing the mass, rolling friction or aerodynamic drag. Some flow control method provides the possibility to modify the flow separation to reduce the development of the swirling structures around the vehicle. In this study, a family van is modeled with a modified form of Ahmed's body by changing the orientation of the flow from its original form (modified/reversed Ahmed body). This model is equipped with a suction on the rear side to comprehensively examine the pressure field modifications that occur. The investigation combines computational and experimental work. Computational approach used a commercial software with standard kepsilon flow turbulence model, and the objectives was to determine the characteristics of the flow field and aerodynamic drag reduction that occurred in the test model. Experimental approach used load cell in order to validate the aerodynamic drag reduction obtained by computational approach. The results show that the application of a suction in the rear part of the van model give the effect of reducing the wake and the vortex formation. Futhermore, aerodynamic drag reduction close to 13.86% for the computational approach and 16.32% for the experimental have been obtained. Abstrak Modifikasi Struktur Aliran pada Model Kendaraan Van dengan Kontrol Aliran Hisapan untuk MengurangiHambatan Aerodinamika. Studi aerodinamika kendaraan biasanya berkaitan dengan keselamatan dan peningkatan efisiensi bahan bakar serta penemuan inovasi baru dalam teknologi kendaraan untuk mengatasi masalah krisis energi dan pemanasan global. Beberapa perusahaan mobil memiliki tujuan untuk mengembangkan solusi kontrol yang memungkinkan pengurangan hambatan aerodinamika kendaraan seiring dengan kemajuan modifikasi kendaraan yang masih dapat dilakukan dengan cara mengurangi massa, rolling friction atau hambatan aerodinamika. Beberapa metode kontrol aliran memberikan kemungkinan dalam memodifikasi pemisahan aliran untuk mengurangi terbentuknya swirling structure di sekitar kendaraan. Dalam studi ini, sebuah kendaraan keluarga dimodelkan dengan memodifikasi Ahmed body dengan mengubah orientasi aliran dari bentuk aslinya (modifikasi Ahmed body/reversed Ahmed body). Model ini dilengkapi dengan hisapan pada sisi belakang untuk memeriksa secara komprehensif perubahan medan tekanan yang terjadi. Penelitian dilakukan dengan pendekatan komputasi dan eksperimental. Pendekatan komputasi menggunakan perangkat lunak komersial dengan model turbulensi aliran k-epsilon standar dan bertujuan untuk mengetahui karakteristik medan aliran dan pengurangan hambatan aerodinamika yang terjadi pada model uji. Pendekatan eksperimental mengg...

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Some Salient Features Of The Time-Averaged Ground Vehicle Wake

Cited by 816 publications

References 4 publications

Assessment of RANS and DES methods for realistic automotive models

Assessment of RANS and DES methods for realistic automotive models

Fluid-structure interaction analysis of rear spoiler vibration for energy harvesting potential

Modification of Flow Structure Over a Van Model by Suction Flow Control to Reduce Aerodynamics Drag

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