A Generative Design and Drag Coefficient Prediction System for Sedan Car Side Silhouettes based on Computational Fluid Dynamics

2019 ◽  
Vol 111 ◽  
pp. 65-79 ◽  
Author(s):  
Erkan Gunpinar ◽  
Umut Can Coskun ◽  
Mustafa Ozsipahi ◽  
Serkan Gunpinar
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Drag Coefficient ◽  
Prediction System ◽  
Generative Design

Drag Reduction of Tractor-Trailers Using Optimized Add-On Devices

2010 ◽  
Vol 132 (8) ◽  
Author(s):  
Fu-Hung Hsu ◽  
Roger L. Davis
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Drag Coefficient ◽  
Body Shape ◽  
Bluff Body ◽  
Navier Stokes ◽  
Optimized Design ◽  
Design Strategies ◽  
Body Design ◽  
Previous Idea

Tractor-trailers have a higher drag coefficient than other vehicles due to their bluff-body shape. Numerous add-on devices have been invented to help reduce drag and fuel consumption. The current research extends our previous idea of add-on humps and investigates their effect in conjunction with curved boat-tail flaps. Computational fluid dynamics in the form of unsteady Reynolds-averaged Navier–Stokes and detached-eddy simulations were used to determine viable design strategies. A 3D baseline computational model was constructed using an Ahmed body. Design optimization was applied on the new add-on devices. The results from the optimized design were shown to have a 50.9% reduction in drag coefficient.

scholarly journals STUDY OF MESH REFINEMENT ON THE AERODYNAMIC COEFFICIENTS FOR NACA2412 PROFILE WITH DIFFERENT ANGLE OF ATTACK AND k - w TURBULENCE MODEL

2020 ◽  
Vol 5 (2) ◽  
Author(s):  
Nícolas Lima Oliveira ◽  
Eric Vargas Loureiro ◽  
Patrícia Habib Hallak
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Drag Coefficient ◽  
Turbulence Model ◽  
Lift Coefficient ◽  
Mesh Refinement ◽  
Angle Of Attack ◽  
Aerodynamic Coefficients ◽  
Computational Fluid Dynamics Cfd

This work presents the studies  obtained using OpenFOAM OpenSource Computational Fluid Dynamics (CFD) Software. Experiments were performed to predict lift coefficient and drag coefficient curves for the NACA2412 profile. Subsequently, the results obtained were compared with the results of the bibliography and discussed.

scholarly journals CFD Investigations of the Effect of Rotating Wheels, Ride Height and Wheelhouse Geometry on the Drag Coefficient of Electric Vehicle

2020 ◽  
Vol 14 ◽  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Drag Coefficient ◽  
Electric Vehicles ◽  
Aerodynamic Drag ◽  
Design Parameters ◽  
Ride Height ◽  
Full Vehicle ◽  
Maximum Range ◽  
Computational Fluid Dynamics Cfd

The development of electric vehicles demands minimizing aerodynamic drag in order to provide maximum range. The wheels contribute significantly to overall drag coefficient value because of flow separation from rims and wheel arches. In this paper various design parameters are investigated and their influence on vehicle drag coefficient is presented. The investigation has been done with the help of computational fluid dynamics (CFD) tools and with implementation of full vehicle setup with rotating wheels. The obtained results demonstrate changes in drag coefficient with respect to the change of design parameters.

Aerodynamic Analysis of a Vehicle Tanker

2009 ◽  
Vol 131 (4) ◽  
Author(s):  
Ramon Miralbes Buil ◽  
Luis Castejon Herrer
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Drag Coefficient ◽  
Aerodynamic Drag ◽  
Positive Impact ◽  
Aerodynamic Resistance ◽  
Independent Contribution ◽  
Aerodynamic Drag Coefficient ◽  
Computational Fluid Dynamics Cfd ◽  
Selection Of

The aim of this article is the presentation of a series of aerodynamic improvements for semitrailer tankers, which reduce the aerodynamic resistance of these vehicles, and, consequently, result in a positive impact on fuel consumption, which is substantially reduced (up to 11%). To make the analysis the computational fluid dynamics (CFD) methodology, using FLUENT, has been used since it allows simulating some geometries and modifications of the geometry without making physical prototypes that considerably increase the time and the economical resources needed. Three improvements are studied: the aerodynamic front, the undercarriage skirt, and the final box adaptor. First they are studied in isolation, so that the independent contribution of each improvement can be appreciated, while helping in the selection of the most convenient one. With the aerodynamic front the drag coefficient has a reduction of 6.13%, with the underskirt 9.6%, and with the boat tail 7.72%. Finally, all the improvements are jointly examined, resulting in a decrease of up to 23% in aerodynamic drag coefficient.

scholarly journals Hydrodynamic Analysis of Different Finger Positions in Swimming: A Computational Fluid Dynamics Approach

2015 ◽  
Vol 31 (1) ◽  
pp. 48-55 ◽  
Author(s):  
J. Paulo Vilas-Boas ◽  
Rui J. Ramos ◽  
Ricardo J. Fernandes ◽  
António J. Silva ◽  
Abel I. Rouboa ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Drag Coefficient ◽  
Hydrodynamic Force ◽  
Lift Coefficient ◽  
Flow Speed ◽  
Cfd Analysis ◽  
Mean Flow ◽  
Hydrodynamic Analysis ◽  
Computational Fluid Dynamics Cfd

The aim of this research was to numerically clarify the effect of finger spreading and thumb abduction on the hydrodynamic force generated by the hand and forearm during swimming. A computational fluid dynamics (CFD) analysis of a realistic hand and forearm model obtained using a computer tomography scanner was conducted. A mean flow speed of 2 m·s−1was used to analyze the possible combinations of three finger positions (grouped, partially spread, totally spread), three thumb positions (adducted, partially abducted, totally abducted), three angles of attack (a = 0°, 45°, 90°), and four sweepback angles (y = 0°, 90°, 180°, 270°) to yield a total of 108 simulated situations. The values of the drag coefficient were observed to increase with the angle of attack for all sweepback angles and finger and thumb positions. For y = 0° and 180°, the model with the thumb adducted and with the little finger spread presented higher drag coefficient values for a = 45° and 90°. Lift coefficient values were observed to be very low at a = 0° and 90° for all of the sweepback angles and finger and thumb positions studied, although very similar values are obtained at a = 45°. For y = 0° and 180°, the effect of finger and thumb positions appears to be much most distinct, indicating that having the thumb slightly abducted and the fingers grouped is a preferable position at y = 180°, whereas at y = 0°, having the thumb adducted and fingers slightly spread yielded higher lift values. Results show that finger and thumb positioning in swimming is a determinant of the propulsive force produced during swimming; indeed, this force is dependent on the direction of the flow over the hand and forearm, which changes across the arm’s stroke.

Computational Fluid Dynamics Simulations in Flow Past Arrays of Finite Plate: Marine Current Energy Harvesting Applications

2017 ◽  
Author(s):  
Bashar Attiya ◽  
I-Han Liu ◽  
Cosan Daskiran ◽  
Jacob Riglin ◽  
Alparslan Oztekin
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Drag Coefficient ◽  
Three Dimensional ◽  
Mean Value ◽  
Wake Flow ◽  
Corner Angle ◽  
Drag Forces ◽  
Computational Fluid Dynamics Simulations ◽  
Dynamics Simulations

Computational fluid dynamics simulations have been conducted for flows past two finite tandem plates at Reynolds number of 50,000. Large Eddy Simulations (LES) were employed in two and three-dimensional geometries to study the interference between tandem plate pair. In order to study the effects of plate corner angle on the flow field and drag forces, two different plate end corners, 90° and a sharp 45° corner angle, were also investigated. The switching from 90° to 45° corners complicate the flow pattern, increase the mean value of drag force and the fluctuations of the drag on the plate. As vortices shed from the upstream plate and reached close proximity to the face of the downstream plate, the vortex cores deformed highly. This behavior reduces the drag coefficient in the downstream plate. Drag coefficient was higher in the 45° case, for both the up and downstream plates by 5% and 10% respectively. Drag coefficient of downstream is recovered almost fully in the 45° case with just 3% difference from the upstream compared to 7% difference in 90° case. Lagrangian Coherent structures were identified and presented in a two-dimensional geometry. This gave a better understanding of the wake flow structure and their influence on the hydrodynamic loading on plates. Contours of vorticity fields and iso-surfaces of Q-criterion, and pressure distribution around the plates were also presented and discussed.

scholarly journals Aerodynamic study of three cars in tandem using computational fluid dynamics

2021 ◽  
Vol 15 (3) ◽  
pp. 8228-8240
Author(s):  
H. Abdul-Rahman ◽  
H. Moria ◽  
Mohammad Rasidi Mohammad Rasani
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Drag Coefficient ◽  
Model Comparison ◽  
Cfd Simulation ◽  
Positive Impact ◽  
Lift Coefficient ◽  
Experimental Studies ◽  
Intelligent Transport System ◽  
Drag Coefficients

Aerodynamics of vehicles account for nearly 80% of fuel losses on the road. Today, the use of the Intelligent Transport System (ITS) allows vehicles to be guided at a distance close to each other and has been shown to help reduce the drag coefficients of the vehicles involved. In this article, the aim is to investigate the effect of distances between a three car platoons, to their drag and lift coefficients, using computational fluid dynamics. To that end, a computational fluid dynamics (CFD) simulation was first performed on a single case and platoon of two Ahmed car models using the STAR-CCM+ software, for validation with previous experimental studies. Significant drop in drag coefficients were observed on platoon models compared to a single model. Comparison between the k-w and k-e turbulence models for a two car platoon found that the k-w model more closely approximate the experimental results with errors of only 8.66% compared to 21.14% by k-e turbulence model. Further studies were undertaken to study the effects of various car gaps (0.5L, 1.0L and 1.5L; L = length of the car) to the aerodynamics of a three-car platoon using CFD simulation. Simulation results show that the lowest drag coefficient that impacts on vehicle fuel savings varies depending on the car's position. For the front car, the lowest drag coefficient (CD) can be seen for car gaps corresponding to X1 = 0.5L and X2 = 0.5L, where CD = 0.1217, while its lift coefficient (CL) was 0.0366 (X1 and X2 denoting first to second and second to third car distance respectively). For the middle car, the lowest drag coefficient occurred when X1 = 1.5L and X2 = 0.5L, which is 0.1397. The lift coefficient for this car was -0.0611. Meanwhile, for the last car, the lowest drag coefficient was observed when X1 = 0.5L and X2 = 1.5L, i.e. CD = 0.263. The lift coefficient for this car was 0.0452. In this study, the lowest drag coefficient yields the lowest lift coefficient. The study also found that for even X1 and X2 spacings, the drag coefficient increased steadily from the front to the last car, while the use of different spacings were found to decrease drag coefficient of the rear car compared to the front car and had a positive impact on platoon driving and fuel-saving.

scholarly journals ANALISIS AERODINAMIKA PADA BODI MOBIL HEMAT ENERGI LINTANG SAMUDRA MENGGUNAKAN METODE COMPUTATIONAL FLUID DYNAMICS

2020 ◽  
Vol 16 (1) ◽  
Author(s):  
Bagus Wahyu Prastyo ◽  
Imam Syafa’at ◽  
Muhammad Dzulfikar
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Drag Coefficient ◽  
Computational Fluid Dynamic ◽  
Fluid Dynamic ◽  
Lift Coefficient

Aerodinamika kendaraan merupakan bentuk pergerakan aliran udara yang memberi pengaruh atau menyebabkan gaya kepada benda saat bergerak dengan kecepatan tertentu. Ada beberapa cara untuk mengetahui bentuk aerodinamika kendaraan. Pertama yaitu melakukan eksperimen dengan memasukkan kendaraan pada terowongan angin. Cara kedua yaitu menggunakan software CFD (Computational fluid dynamic). Dengan metode CFD peneliti dapat membuat berbagai bentuk desain tanpa mengeluarkan biaya tambahan. Penelitian ini bertujuan untuk mengetahui aerodinamika serta nilai Drag coefficient (CD) dan Lift coefficient (CL) pada bodi mobil Lintang Samudra. Simulasi dilakukan pada 4 kecepatan aliran udara yaitu 40, 50,60 dan 70 km/h. Simulasi menggunakan model turbulensi k-ɛ dengan intensitas 5%, model tersebut dipilih karena memiliki tingkat error terkecil terhadap validasi dari jurnal simulasi Bammidi dan Murty (2014) sebesar 0,13 %. Didapatkan hasil bodi Lintang Samudra 1 memiliki nilai CD = 0,07598 - 0,07025 dan CL=(-0,00800) – (-0,00837) Pada bodi Lintang Samudra 2 memiliki nilai CD = 0,072451 - 0,067020 dan CL = 0,001395 – 0,000949. Terdapat perbedaan bentuk aliran fluida pada bodi Lintang Samudra 1dan bodi Lintang Samudra 2. Jadi bodi kedua lebih aerodinamis dari bodi pertama. Kata kunci: aerodinamika, bodi, CFD, drag, lift.

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