Parametric Study of Drag Force on a Formula Student Electric Race Car Using CFD

2014 ◽  
Vol 575 ◽  
pp. 300-305 ◽  
Author(s):  
Lalit Patidar ◽  
Sri Ramya Bhamidipati
Keyword(s):  
Drag Force ◽  
Fuel Economy ◽  
Aerodynamic Drag ◽  
Pressure Coefficient ◽  
Substantial Reduction ◽  
Frontal Area ◽  
Test Case ◽  
Electric Cars ◽  
Race Car ◽  
Set Up

Aerodynamic drag plays an important role in fuel economy of the vehicle especially for electric cars directly affecting the range. The objective of Aerodynamics subsystem of IIT Bombay racing team is to predict and minimize drag force on the Formula student electric race car thereby improving the performance. A standard generic car body known as Ahmed body is taken to set up simulation parameters in FLUENT by validating a test case against the experimental data available in literature. Variation and dependence of drag force on parameters such as frontal area, distribution of pressure coefficient and pressure loss in wake region is studied numerically. Comparison is made between Formula Student 2013 car Evo2 and newly designed car Evo3 for coming season of Formula Student 2014. A substantial reduction in drag force of 18.8% is achieved which can be attributed to lower frontal area and streamlined bodyworks design. Energy consumption of the vehicle for endurance race is reduced by 11.5 % improving the fuel economy.

Methodology for the Estimation of the Aerodynamic Drag Parameters of Cyclists

2019 ◽  
Author(s):  
Alejandra Polanco ◽  
Juan Fuentes ◽  
Sebastián Porras ◽  
Daniel Castiblanco ◽  
Julián Uribe ◽  
...  
Keyword(s):  
Drag Force ◽  
Aerodynamic Drag ◽  
Cycling Performance ◽  
Experimental Methodology ◽  
Frontal Area ◽  
Relevant Effect ◽  
Aerodynamic Parameters ◽  
Resistive Forces ◽  
Drag Area

Abstract The aerodynamic drag force has a relevant effect on cycling performance since it is one of the major resistive forces acting on the bicycle. For this reason, this paper presents the development of an experimental methodology to estimate the aerodynamic parameters of a bicycle-cyclist set. The methodology combines outdoor measurements to estimate the drag area with indoor measurements to measure the projected frontal area. The methodology was implemented to quantify the effect of posture in the aerodynamic parameters of a group of cyclists. The tests were performed to characterize the drag parameters associated with three postures defined by the position of the grip on the handlebar: tops, hoods, and drops. Significant differences in the aerodynamic parameters were found for the postures studied through the proposed methodology. The posture variation led to reductions of up to 11.8% in the drag area of the cyclists when passing from tops to drops posture. The results obtained are in agreement with the literature indicating that the implementation of the methodology is feasible for the estimation of the aerodynamic parameters in cycling.

scholarly journals Estimating Cycling Aerodynamic Performance Using Anthropometric Measures

2020 ◽  
Vol 10 (23) ◽  
pp. 8635
Author(s):  
Raman Garimella ◽  
Thomas Peeters ◽  
Eduardo Parrilla ◽  
Jordi Uriel ◽  
Seppe Sels ◽  
...  
Keyword(s):  
Drag Force ◽  
Joint Angle ◽  
Aerodynamic Drag ◽  
Linear Regression Analysis ◽  
3D Models ◽  
Frontal Area ◽  
Coefficient Of Determination ◽  
Anthropometric Measures ◽  
Aerodynamic Efficiency ◽  
Angle Data

Aerodynamic drag force and projected frontal area (A) are commonly used indicators of aerodynamic cycling efficiency. This study investigated the accuracy of estimating these quantities using easy-to-acquire anthropometric and pose measures. In the first part, computational fluid dynamics (CFD) drag force calculations and A (m2) values from photogrammetry methods were compared using predicted 3D cycling models for 10 male amateur cyclists. The shape of the 3D models was predicted using anthropometric measures. Subsequently, the models were reposed from a standing to a cycling pose using joint angle data from an optical motion capture (mocap) system. In the second part, a linear regression analysis was performed to predict A using 26 anthropometric measures combined with joint angle data from two sources (optical and inertial mocap, separately). Drag calculations were strongly correlated with benchmark projected frontal area (coefficient of determination R2 = 0.72). A can accurately be predicted using anthropometric data and joint angles from optical mocap (root mean square error (RMSE) = 0.037 m2) or inertial mocap (RMSE = 0.032 m2). This study showed that aerodynamic efficiency can be predicted using anthropometric and joint angle data from commercially available, inexpensive posture tracking methods. The practical relevance for cyclists is to quantify and train posture during cycling for improving aerodynamic efficiency and hence performance.

Wind Tunnel Experiments to Assess the Effect of Back-Mounted Radio Transmitters on Bird Body Drag

1988 ◽  
Vol 135 (1) ◽  
pp. 265-273 ◽  
Author(s):  
HOLLIDAY H. OBRECHT ◽  
C. J. PENNYCUICK ◽  
MARK R. FULLER
Keyword(s):  
Wind Tunnel ◽  
Aerodynamic Drag ◽  
Substantial Reduction ◽  
Frontal Area ◽  
Flight Performance ◽  
Wind Tunnel Experiments ◽  
Front End ◽  
Body Drag ◽  
Radio Transmitters ◽  
Performance Estimates

To whom reprint requests should be addressed. The aerodynamic drag of bird bodies was measured in a wind tunnel, with and without back-mounted dummy radio transmitters. Flight performance estimates indicate that the drag of a large transmitter can cause a substantial reduction of a migrant's range, that is, the distance it can cover in non-stop flight. The drag of the transmitter can be reduced by arranging the components in an elongated shape, so minimizing the frontal area. The addition of a rounded fairing to the front end, and a pointed fairing behind, was found to reduce the drag of the transmitter by about onethird, as compared with an unfaired rectangular box.

scholarly journals Drag Reduction by Application of Aerodynamic Devices in a Race Car

2020 ◽  
Author(s):  
Devang S. Nath ◽  
Prashant Chandra Pujari ◽  
Amit Jain ◽  
Vikas Rastogi
Keyword(s):  
Drag Force ◽  
Fuel Economy ◽  
High Speed ◽  
Three Dimensional ◽  
Environmental Policies ◽  
Fuel Prices ◽  
Race Car ◽  
Car Model ◽  
High Speeds ◽  
Computational Fluid Dynamics Cfd

Abstract In this era of fast-depleting natural resources, the hike in fuel prices is ever-growing. With stringent norms over environmental policies, the automotive manufacturers are on a voyage to produce efficient vehicles with lower emissions. High-speed cars are at a stake to provide uncompromised performance but having strict rules over emissions drives the companies to approach through a different route to keep the demands of performance intact. One of the most sought-after ways is to improve the aerodynamics of the vehicles. Drag force is one of the major setbacks when it comes to achieving high speeds when the vehicle is in motion. This research aims to examine the effects of different add on devices on the vehicle to reduce drag and make the vehicle aerodynamically streamlined. A more streamlined vehicle will be able to achieve high speeds and consequently, the fuel economy is also improved. The three-dimensional car model is developed in SOLIDWORKS v17. Computational Fluid Dynamics (CFD) is performed to understand the effects of these add on devices. CFD is carried out in the ANSYSTM 17.0 Fluent module. Drag Coefficient (CD) and Drag Force is calculated and is compared in different cases.

The Emergence of Rabbinic Culture from the Perspective of Qumran

2015 ◽  
Vol 6 (2) ◽  
pp. 253-274
Author(s):  
Vered Noam
Keyword(s):  
Early Stage ◽  
Second Temple ◽  
Test Case ◽  
Literary Works ◽  
Jewish Culture ◽  
The Bible ◽  
Set Up

The rabbinic halakhic system, with its many facets and the literary works that comprise it, reflects a new Jewish culture, almost completely distinct in its halakhic content and scope from the biblical and postbiblical culture that preceded it. By examining Jewish legislation in the area of corpse impurity as a test case, the article studies the implications of Qumranic halakhah, as a way-station between the Bible and the Mishnah, for understanding how Tannaitic halakhah developed. The impression obtained from the material reviewed in the article is that the direction of the “Tannaitic revolution” was charted, its methods set up, and its principles established, at a surprisingly early stage, before the destruction of the Second Temple, and thus at the same time that the Qumran literature was created.

scholarly journals Optimization of a WGA-Free Molecular Tagging-Based NGS Protocol for CTCs Mutational Profiling

2020 ◽  
Vol 21 (12) ◽  
pp. 4364
Author(s):  
Giuseppa De Luca ◽  
Barbara Cardinali ◽  
Lucia Del Mastro ◽  
Sonia Lastraioli ◽  
Franca Carli ◽  
...  
Keyword(s):  
Substantial Reduction ◽  
Breast Cancer Patients ◽  
Dna Templates ◽  
Molecular Tagging ◽  
Mutational Profiling ◽  
Optimized Protocol ◽  
Set Up ◽  
Detection Of Mutations ◽  
Almost All ◽  
Next Generation Sequencing Ngs

Molecular characterization of Circulating Tumor Cells (CTCs) is still challenging, despite attempts to minimize the drawbacks of Whole Genome Amplification (WGA). In this paper, we propose a Next-Generation Sequencing (NGS) optimized protocol based on molecular tagging technology, in order to detect CTCs mutations while skipping the WGA step. MDA-MB-231 and MCF-7 cell lines, as well as leukocytes, were sorted into pools (2–5 cells) using a DEPArray™ system and were employed to set up the overall NGS procedure. A substantial reduction of reagent volume for the preparation of libraries was performed, in order to fit the limited DNA templates directly derived from cell lysates. Known variants in TP53, KRAS, and PIK3CA genes were detected in almost all the cell line pools (35/37 pools, 94.6%). No additional alterations, other than those which were expected, were found in all tested pools and no mutations were detected in leukocytes. The translational value of the optimized NGS workflow is confirmed by sequencing CTCs pools isolated from eight breast cancer patients and through the successful detection of variants. In conclusion, this study shows that the proposed NGS molecular tagging approach is technically feasible and, compared to traditional NGS approaches, has the advantage of filtering out the artifacts generated during library amplification, allowing for the reliable detection of mutations and, thus, making it highly promising for clinical use.

Aerodynamics of Cyclist Posture, Bicycle and Helmet Characteristics in Time Trial Stage

2012 ◽  
Vol 28 (3) ◽  
pp. 317-323 ◽  
Author(s):  
Vincent Chabroux ◽  
Caroline Barelle ◽  
Daniel Favier
Keyword(s):  
Statistical Analysis ◽  
Wind Tunnel ◽  
Drag Coefficient ◽  
Drag Force ◽  
Time Trial ◽  
Frontal Area ◽  
Significant Gain ◽  
Upper Limbs ◽  
Force Coefficient ◽  
Coefficient Reduction

The present work is focused on the aerodynamic study of different parameters, including both the posture of a cyclist’s upper limbs and the saddle position, in time trial (TT) stages. The aerodynamic influence of a TT helmet large visor is also quantified as a function of the helmet inclination. Experiments conducted in a wind tunnel on nine professional cyclists provided drag force and frontal area measurements to determine the drag force coefficient. Data statistical analysis clearly shows that the hands positioning on shifters and the elbows joined together are significantly reducing the cyclist drag force. Concerning the saddle position, the drag force is shown to be significantly increased (about 3%) when the saddle is raised. The usual helmet inclination appears to be the inclination value minimizing the drag force. Moreover, the addition of a large visor on the helmet is shown to provide a drag coefficient reduction as a function of the helmet inclination. Present results indicate that variations in the TT cyclist posture, the saddle position and the helmet visor can produce a significant gain in time (up to 2.2%) during stages.

Research on Torque Distribution Strategy for ISG Hybrid Electric Cars

2012 ◽  
Vol 546-547 ◽  
pp. 212-217
Author(s):  
Xu Dong Wang ◽  
Hai Xing Zhang ◽  
Shu Cai Yang ◽  
Yong Qin Zhou ◽  
Jin Fa Liu
Keyword(s):  
Hybrid System ◽  
Fuel Economy ◽  
Test Model ◽  
Torque Distribution ◽  
Electric Cars ◽  
Distribution Strategy ◽  
Hybrid Car ◽  
Total Vehicle ◽  
Hybrid Electric ◽  
Minimum Work

Based on the configuration and working state analysis of the ISG hybrid electric cars, the torque distribution strategy of a hybrid system is designed to delineate the maximum and minimum work torque curves of the engine, achieve optimization of engine’s range so as to make sure the target torque of the engine and ISG motor, and finally through the calibrated driving characteristics MAP and battery SOC state to achieve the calculation of total vehicle torque demand. Taking the Hafei Saibao ISG hybrid car as a test model, the test of fuel economy and emissions carried out under specific conditions showed that using the torque distribution strategy has increased by 12.8 % of the ISG hybrid car fuel economy and improved emissions performance to some extent compared to the traditional Hafei Saibao cars.

scholarly journals Comparison of Typical Controllers for Direct Yaw Moment Control Applied on an Electric Race Car

Vehicles ◽  
2021 ◽  
Vol 3 (1) ◽  
pp. 127-144
Author(s):  
Andoni Medina ◽  
Guillermo Bistue ◽  
Angel Rubio
Keyword(s):  
Handling Performance ◽  
Electric Cars ◽  
Control Techniques ◽  
Race Car ◽  
Yaw Rate ◽  
Direct Yaw Moment Control ◽  
Yaw Moment Control ◽  
Moment Control ◽  
Race Track ◽  
Yaw Moment

Direct Yaw Moment Control (DYC) is an effective way to alter the behaviour of electric cars with independent drives. Controlling the torque applied to each wheel can improve the handling performance of a vehicle making it safer and faster on a race track. The state-of-the-art literature covers the comparison of various controllers (PID, LPV, LQR, SMC, etc.) using ISO manoeuvres. However, a more advanced comparison of the important characteristics of the controllers’ performance is lacking, such as the robustness of the controllers under changes in the vehicle model, steering behaviour, use of the friction circle, and, ultimately, lap time on a track. In this study, we have compared the controllers according to some of the aforementioned parameters on a modelled race car. Interestingly, best lap times are not provided by perfect neutral or close-to-neutral behaviour of the vehicle, but rather by allowing certain deviations from the target yaw rate. In addition, a modified Proportional Integral Derivative (PID) controller showed that its performance is comparable to other more complex control techniques such as Model Predictive Control (MPC).

Role of Trip Information Preview in Fuel Economy of Plug-In Hybrid Vehicles

2009 ◽  
Author(s):  
Chen Zhang ◽  
Ardalan Vahidi ◽  
Xiaopeng Li ◽  
Dean Essenmacher
Keyword(s):  
Dynamic Programming ◽  
Fuel Economy ◽  
Substantial Reduction ◽  
Hybrid Vehicles ◽  
Hilly Terrain ◽  
Additional Increase ◽  
Charging Station ◽  
Complete Knowledge ◽  
Deterministic Dynamic

This paper investigates the role of partial or complete knowledge of future driving conditions in fuel economy of Plug-in Hybrid Vehicles (PHEVs). We show that with the knowledge of distance to the next charging station only, substantial reduction in fuel use, up to 18%, is possible by planning a blended utilization of electric motor and the engine throughout the entire trip. To achieve this we formulate a modified Equivalent Consumption Minimization Strategy (ECMS) which takes into account the traveling distance. We show further fuel economy gain, in the order of 1–5%, is possible if the future terrain and velocity are known; we quantify this additional increase in fuel economy for a number of velocity cycles and a hilly terrain profile via deterministic dynamic programming.

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