Shape modification of Ahmed body to reduce drag coefficient and determination of turbulence model

Şumnu, Ahmet

doi:10.28948/ngumuh.879584

Cited by 4 publications

(6 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The RNG k-ε turbulence method is suitable for ground vehicles since it gives more accurate results. The study of Şumnu [27] investigated different turbulence models to show which one is in good agreement with experimental results. Table 1 shows the drag coefficient values CD for five different turbulence models and their differences from the experimental result that is reported by Meile et al [31].…”

Section: Grid Independence and Cfd Validation Processmentioning

confidence: 75%

“…It can be observed that the solution result of RNG k-ε turbulence model is close to the experimental value. In addition, the solution results are compared with both experimental data [31] and CFD results [27] to validate this study at 40 m/s and Reynolds number (length based on body) of 2.78×10 6 . Table 2 presents drag coefficient values for body without a control rod.…”

Section: Grid Independence and Cfd Validation Processmentioning

confidence: 99%

“…Some flow regulation may be performed with shape modifications to increase aerodynamic performance. Şumnu [27] studied Ahmed body aerodynamics by modifying the shape and reducing the aerodynamic drag coefficient. In addition, different turbulence models were used to perform the solution and find the proper model as RNG k-ε.…”

Section: Introductionmentioning

confidence: 99%

“…Drag coefficient values and their differences between experimental results and solutions for selected turbulence models[27] …”

mentioning

confidence: 99%

See 3 more Smart Citations

Passive Flow Control of Ahmed Body using Control Rod

Şumnu

2022

Int. J. Automot. Mech. Eng.

View full text Add to dashboard Cite

In the current study, numerical analysis of passive control flow with a control rod for Ahmed body is performed at different slant angles and velocities and placed rod locations on the slant surface. The aim of the study is to improve aerodynamic performance by preventing flow separation on the slant surface of Ahmed body using a control rod. This passive flow control method uses a control rod that has not been applied for simplified ground vehicles before. Therefore, it can be said that this study is a new example in point of a passive flow control application for Ahmed body. The solution of the study is performed by using the Computational Fluid Dynamics (CFD) method. The solutions are firstly performed for baseline geometry, and the results are compared with experimental data reported in the literature for validation. CFD solutions are carried out by means of the ANSYS and RNG k- turbulence model is used to simulate flow-field since it captures the effect of turbulent flow. The solutions used a control rod with a 20 mm diameter performed at a dimensionless location (X/L=0.057 and 0.153) for Ahmed body. The results are presented visually in the figures, and drag coefficient values are also given in Table format. It is concluded that the rod application is useful for some specified slant angles and velocities since flow separation delays and suppresses the slant surface. The maximum drag reduction is achieved at about 6.153% at a slant angle of 35° and 20 m/s velocity of air, and location of control rod of 0.057, while the minimum drag reduction is about 1.048% at slant angle of 25° and velocity of air at 40 m/s and location of control rod of 0.153.

show abstract

Section: Grid Independence and Cfd Validation Processmentioning

confidence: 75%

Section: Grid Independence and Cfd Validation Processmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

“…Drag coefficient values and their differences between experimental results and solutions for selected turbulence models[27] …”

mentioning

confidence: 99%

See 2 more Smart Citations

Passive Flow Control of Ahmed Body using Control Rod

Şumnu

2022

Int. J. Automot. Mech. Eng.

View full text Add to dashboard Cite

show abstract

“…In this study, RNG (Re-Normalisation Group) k-ε turbulence model was used since this turbulence model simulates accurately flow field for this specified conditions [39]. This model is renormalized the Navier-Stokes equations and take into account smaller motion effect.…”

Section: Numeric Solutionmentioning

confidence: 99%

Bir Kara Aracının Aerodinamik Sürüklenmesi Üzerine Yan Cihazların ve Yan Rüzgâr Akışının Etkisinin İncelenmesi

Şumnu

2022

Çukurova Üniversitesi Mühendislik Fakültesi Dergisi

View full text Add to dashboard Cite

In the present study, effect of side devices and crosswind flow are investigated to observe aerodynamic drag coefficient for a simplified ground vehicle (Ahmed body) since it directly effects fuel consumption. When the literature was examined, the studies that were investigated effect of slant angle, velocity and geometric modifications were presented. However, there are few studies that proposed both side device effect and crosswind flow for ground vehicles at different yaw angles. The CFD (Computational Fluid Dynamic) solution is performed both model with side devices and crosswind flow condition. The crosswind flow condition has been analyzed at different yaw angles (β=5°, 10°, 20°, and 30°) to observe how to affected drag coefficient. Pressure contours have been presented for model with and without side devices and under the crosswind flow conditions at rear region of body since the most of the drag force occurs flow separation or adverse pressure gradient. The streamlines velocities have been presented at x-plane which is positioned side devices location under the crosswind flow conditions. In addition, vorticity magnitude has been given for both models with and without side devices at different yaw angle. In the results of study are observed that side devices adversely effects aerodynamic performance since flow separation occurs on the side of body and it causes to increase pressure drag. The pressure drop is also observed at rear region of model due to crosswind flow condition. This causes the increase of drag forces.

show abstract

Yan rüzgar koşullarında ön kısmı düz plakalı bir otobüs modeli üzerindeki direncin düşürülmesi

Seyhan

Fırat

2022

NÖHÜ Müh. Bilim. Derg.

View full text Add to dashboard Cite

Akaryakıt fiyatları ve insanların çevrenin mevcut durumu üzerinde meydana getirdiği değişimler ticari taşıtların yakıt ekonomisinin iyileştirilmesine olan ilgiyi arttırmıştır. Büyük olasılıkla, bir taşıtın yakıt ekonomisini iyileştirmenin en ekonomik yolu taşıtı aerodinamik açıdan daha verimli yapmaktır. Mevcut çalışma, sıfır ve sıfırdan farklı sapma açılarında (β≤9°) 1:25 ölçekli otobüs modelinin ön alt yüzeyine paralel ve modele göre daha önde olacak şekilde yerleştirilen düz plakaların aerodinamik performansını deneysel olarak araştırmayı amaçlamaktadır. Kıyaslama çalışmaları, düz plakasız otobüs modelini de hesaba katarak, genişliğe-dayalı Reynolds sayısının Rew=104000±3000 değerinde gerçekleştirilmiştir. Sıfır sapma açısında, otobüs genişliğinin (w) onda yedisi kadar genişlikli bir plakanın 0,16w daha önüne yerleştirildiği bir geometrik kurulum plakasız otobüs modeline etkiyeninkinin %92,9’u kadarlık bir zaman-ortalamalı direnç katsayısına, , yol açmaktadır. Bu kurulumun, yan akış şartları altında ’yi düşürmede de etkin olduğu görülmüştür.

show abstract

Shape modification of Ahmed body to reduce drag coefficient and determination of turbulence model

Cited by 4 publications

References 24 publications

Passive Flow Control of Ahmed Body using Control Rod

Passive Flow Control of Ahmed Body using Control Rod

Bir Kara Aracının Aerodinamik Sürüklenmesi Üzerine Yan Cihazların ve Yan Rüzgâr Akışının Etkisinin İncelenmesi

Yan rüzgar koşullarında ön kısmı düz plakalı bir otobüs modeli üzerindeki direncin düşürülmesi

Contact Info

Product

Resources

About