Methodology Development to Accurately Predict Aerodynamic Drag and Lift for Passenger Vehicles Using CFD.

2016 ◽  
Author(s):  
Pruthviraj Mohanrao Palaskar ◽  
Vivek Kumar ◽  
Rohit Vaidya
Keyword(s):  
Aerodynamic Drag ◽  
Methodology Development ◽  
Passenger Vehicles ◽  
Drag And Lift

CFD Approach to Evaluate Wind-Tunnel and Model Setup Effects on Aerodynamic Drag and Lift for Detailed Vehicles

2010 ◽  
Author(s):  
Oliver Fischer ◽  
Timo Kuthada ◽  
Edzard Mercker ◽  
Jochen Wiedemann ◽  
Bradley Duncan
Keyword(s):  
Wind Tunnel ◽  
Aerodynamic Drag ◽  
Drag And Lift ◽  
Model Setup

scholarly journals Design of electromechanical height adjustable suspension

2017 ◽  
Vol 232 (9) ◽  
pp. 1253-1269 ◽  
Author(s):  
Nicola Amati ◽  
Andrea Tonoli ◽  
Luca Castellazzi ◽  
Sanjarbek Ruzimov
Keyword(s):  
Aerodynamic Drag ◽  
High Reliability ◽  
Environmental Issues ◽  
Emissions Reduction ◽  
General Context ◽  
Passenger Vehicles ◽  
Potential Benefits ◽  
Vehicle Motion ◽  
Low Costs ◽  
Fuel Consumption And Emissions

In the general context of vehicles’ fuel consumption and emissions reduction, the minimization of the aerodynamic drag can offer not negligible benefits regarding the environmental issues. The adjustment of the vehicle height is one of the possible ways to provide a reduction of the resistances to vehicle motion, in addition to consequent aspects regarding the increased versatility of the vehicle. The aim of this paper is to present in a systematic way the state of the art of height adjustment systems for passenger vehicles, summarizing the main modes of operations, working principles, and architectures. Particular attention is then given to electromechanical systems, which represent the next trends for future vehicles due to their high reliability and relatively low costs. A design methodology for electromechanical height adjustment systems with the purpose of optimizing their performance is presented. Such procedure is able to reach the most efficient working point even in presence of constraints of different nature. Prototypes have been designed, produced and tested to demonstrate the potentialities of electromechanical height adjustment systems. Furthermore, potential benefits and drawbacks of using such systems are highlighted.

Experimental Studies on Aerodynamic Characteristics of Pantograph System According to the Pantograph Cover Configurations for High Speed Train

2011 ◽  
Author(s):  
Yeongbin Lee ◽  
Minho Kwak ◽  
Kyu Hong Kim ◽  
Dong-Ho Lee
Keyword(s):  
Wind Tunnel ◽  
High Speed ◽  
Aerodynamic Drag ◽  
Aerodynamic Force ◽  
Experimental Studies ◽  
Wind Tunnel Test ◽  
Aerodynamic Characteristics ◽  
Experimental Models ◽  
High Speed Train ◽  
Drag And Lift

In this study, the aerodynamic characteristics of pantograph system according to the pantograph cover configurations for high speed train were investigated by wind tunnel test. Wind tunnel tests were conducted in the velocity range of 20∼70m/s with scaled experimental pantograph models. The experimental models were 1/4 scaled simplified pantograph system which consists of a double upper arm and a single lower arm with a square cylinder shaped panhead. The experimental model of the pantograph cover is also 1/4 scaled and were made as 4 different configurations. It is laid on the ground plate which modeled on the real roof shape of the Korean high speed train. Using a load cell, the aerodynamic force such as a lift and a drag which were acting on pantograph system were measured and the aerodynamic effects according to the various configurations of pantograph covers were investigated. In addition, the total pressure distributions of the wake regions behind the panhead of the pantograph system were measured to investigate the variations of flow pattern. From the experimental test results, we checked that the flow patterns and the aerodynamic characteristics around the pantograph systems are varied as the pantograph cover configurations. In addition, it is also found that pantograph cover induced to decrease the aerodynamic drag and lift forces. Finally, we proposed the aerodynamic improvement of pantograph cover and pantograph system for high speed train.

scholarly journals Drag reduction mechanisms on a generic square-back vehicle using an optimised yaw-insensitive base cavity

2021 ◽  
Vol 62 (12) ◽  
Author(s):  
Magnus Urquhart ◽  
Max Varney ◽  
Simone Sebben ◽  
Martin Passmore
Keyword(s):  
Bluff Body ◽  
Greenhouse Gas Emission ◽  
Aerodynamic Drag ◽  
Base Flow ◽  
Key Factors ◽  
Passenger Vehicles ◽  
Reduction Mechanisms ◽  
Image Velocimetry ◽  
Base Cavity ◽  
Tapered Cavity

AbstractRegulations on global greenhouse gas emission are driving the development of more energy-efficient passenger vehicles. One of the key factors influencing energy consumption is the aerodynamic drag where a large portion of the drag is associated with the base wake. Environmental conditions such as wind can increase the drag associated with the separated base flow. This paper investigates an optimised yaw-insensitive base cavity on a square-back vehicle in steady crosswind. The test object is a simplified model scale bluff body, the Windsor geometry, with wheels. The model is tested experimentally with a straight cavity and a tapered cavity. The taper angles have been optimised numerically to improve the robustness to side wind in relation to drag. Base pressures and tomographic Particle Image Velocimetry of the full wake were measured in the wind tunnel. The results indicate that a cavity decreases the crossflow within the wake, increasing base pressure, therefore lowering drag. The additional optimised cavity tapering further reduces crossflow and results in a smaller wake with less losses. The overall wake unsteadiness is reduced by the cavity by minimising mixing in the shear layers as well as dampening wake motion. However, the coherent wake motions, indicative of a balanced wake, are increased by the investigated cavities. Graphical abstract

Examining the Aerodynamic Drag and Lift Characteristics of a Newly Developed Elliptical-Bladed Savonius Rotor

2019 ◽  
Vol 141 (5) ◽  
Author(s):  
Nur Alom ◽  
Ujjwal K. Saha
Keyword(s):  
Wind Tunnel ◽  
Stokes Equations ◽  
Aerodynamic Drag ◽  
Three Dimensional ◽  
Turbine Rotor ◽  
Wind Tunnel Experiments ◽  
Drag Forces ◽  
Velocity Magnitude ◽  
Bladed Rotor ◽  
Drag And Lift

The elliptical-bladed Savonius wind turbine rotor has become a subject of interest because of its better energy capturing capability. Hitherto, the basic parameters of this rotor such as overlap ratio, aspect ratio, and number of blades have been studied and optimized numerically. Most of these studies estimated the torque and power coefficients (CT and CP) at given flow conditions. However, the two important aerodynamic forces, viz., the lift and the drag, acting on the elliptical-bladed rotor have not been studied. This calls for a deeper investigation into the effect of these forces on the rotor performance to arrive at a suitable design configuration. In view of this, at the outset, two-dimensional (2D) unsteady simulations are conducted to find the instantaneous lift and drag forces acting on an elliptical-bladed rotor at a Reynolds number (Re) = 0.892 × 105. The shear stress transport (SST) k–ω turbulence model is used for solving the unsteady Reynolds averaged Navier–Stokes equations. The three-dimensional (3D) unsteady simulations are then performed which are then followed by the wind tunnel experiments. The drag and lift coefficients (CD and CL) are analyzed for 0–360 deg rotation of rotor with an increment of 1 deg. The total pressure, velocity magnitude, and turbulence intensity contours are obtained at various angles of rotor rotation. For the elliptical-bladed rotor, the average CD, CL, and CP, from 3D simulation, are found to be 1.31, 0.48, and 0.26, respectively. The average CP for the 2D elliptical profile is found to be 0.34, whereas the wind tunnel experiments demonstrate CP to be 0.19.

scholarly journals Investigation of Drag and Lift Forces over the Profile of Car with Rearspoiler using CFD

2015 ◽  
Vol 1 (8) ◽  
pp. 331
Author(s):  
Naveen Kumar Velagapudi ◽  
Lalit Narayan K. ◽  
L. N. V. Narasimha Rao ◽  
Sri Ram Y.
Keyword(s):  
Drag Force ◽  
High Speed ◽  
Aerodynamic Drag ◽  
Fuel Utilization ◽  
Ansys Fluent ◽  
Total Drag ◽  
Rear Spoiler ◽  
Computational Fluid Dynamics Cfd ◽  
Lift Forces ◽  
Drag And Lift

Now a days demand of a high speed car is increasing in which vehicle stability is of major concern. Forces like drag& lift,weight,side forces and thrust acts on a vehicle when moving on road which significantly effect the fuel consumption The drag force is produced by relative motion between air and vehicle and about 60% of total drag is produced at the rear end. Reduction of drag force at the rear end improves the fuel utilization. This work aims to reduce the drag force which improves fuel utilization and protects environment as well. In the stage of work a sedan car with different types of spoilers are used to reduce the aerodynamic drag force. The design of sedan car has been done on CATIA-2010 and the same is used for analysis in ANSYS-(fluent). The analysis is done for finding out drag and lift forces at different velocities, and spoilers. This study proposes an effective numerical model based on the computational fluid dynamics (CFD) approach to obtain the flow structure around a passenger car with a rear spoiler

scholarly journals Investigation of the Aerodynamic Drag of Baseballs with Gyro Spin

Proceedings ◽  
2020 ◽  
Vol 49 (1) ◽  
pp. 162
Author(s):  
Bin Lyu ◽  
Jeff Kensrud ◽  
Lloyd Smith
Keyword(s):  
Aerodynamic Drag ◽  
Spin Axis ◽  
Laboratory Setting ◽  
Spin Orientation ◽  
Axis Parallel ◽  
Drag And Lift

The following considers drag measurements of baseballs with backspin (spin axis horizontal and normal to trajectory) and gyro spin (spin axis parallel to trajectory) orientations. Balls were propelled through still air in a laboratory setting at 36 m/s and spin ranging from 1250 rpm to 1750 rpm. Balls were projected with backspin and gyro spin in the two- and four-seam orientations. Speed and position sensors measured the speed and location of the balls at three locations from which the coefficient of drag and lift were found. Drag was observed to depend on spin rate, spin axis and seam orientation. The largest and smallest coefficient of drag was found with the gyro four-seam and two-seam spin orientation, respectively. Drag was observed to correlate with seam height with back spin, but not with gyro spin. Lift was observed for baseballs with back spin, but not with gyro spin.

Aerodynamic Analysis of the Preliminary Design of SURIAKAR 4 Using CFD

2014 ◽  
Vol 629 ◽  
pp. 507-512
Author(s):  
Lai Gwo Sung ◽  
Wan Zaidi Wan Omar ◽  
Ahmad Zafri Zainudin ◽  
S. Mansor ◽  
Tholudin Mat Lazim
Keyword(s):  
Aerodynamic Drag ◽  
Aerodynamic Characteristics ◽  
Rear Wheel ◽  
Preliminary Design ◽  
Ansys Fluent ◽  
Design Speed ◽  
Drag And Lift ◽  
The Stability ◽  
The Right ◽  
Grid Independence

A four-wheel solar car, the SURIAKAR 4, was designed based on the revised regulations of the Challenger Class World Solar Challenge (2013). It is a four-wheel car with the front and back wheels enclosed in a wind cheating cover. The cockpit is located in such a way that it sits between the front and rear wheel, within the wheel cover on the right side of the car. This paper investigates the aerodynamic characteristics of the car, especially the drag and lift forces, and other forces and moments that determine the stability of the car using CFD package ANSYS Fluent. The model analysis was done with 2.23 million elements after a thorough grid independence study was conducted. The drag coefficient of SURIAKAR 4 is 0.1817. With a frontal area of 0.8934 m2 and at the design speed, the car requires 2132 W of power to overcome this aerodynamic drag. The results also showed that the airflow quality around the car is relatively well-behaved, with only a few turbulent flow points identified. This flow incurs drag penalty and thus have to be modified.

scholarly journals Аэродинамический профиль в трансзвуковом потоке газа

2021 ◽  
pp. 20-27
Author(s):  
Юрий Александрович Крашаница ◽  
Дмитрий Юрьевич Жиряков
Keyword(s):  
Numerical Methods ◽  
Transonic Flow ◽  
Center Of Pressure ◽  
Aerodynamic Drag ◽  
Aerodynamic Characteristics ◽  
Operating Conditions ◽  
Pressure Coefficients ◽  
Standard Atmosphere ◽  
Drag And Lift ◽  
Cae System

The subject of investigation in this article is transonic flow. This is a condition in which local speeds of sound are appears on the wing surface, even at the subsonic speed of the nonturbulent flow. As a result, at a certain speed of the incoming flow, the flow regime around the aerodynamic surface will change sharply, which in turn changes the aerodynamic characteristics. Aerodynamic surfaces of the most transport category airplane experience transonic airflow during flight. The goal of the investigation is to study aerodynamic characteristics using numerical methods. The use of numerical methods in the design of aircraft structures is used more and more often to determine the optimal parameters for given operating conditions. This contributes to obtaining a more optimal and perfect design. In this article, we carried out a numerical analysis of the aerodynamic characteristics of airfoils in the transonic flow case using the CAE system CFD ANSYS. As a result of the research, the distributions of the pressure coefficients over the profile surface were obtained. The nature of the flow is obtained, which is similar to the picture of the pressure coefficients for transonic flow in the published sources of this topic. In the area of the middle of the profile, a shock-wave is observed. As a result, the flow around the airfoil changes, which contributes to a change in aerodynamic characteristics. The behavior of the aerodynamic drag and lift coefficients depending on the speed of the Mach number is considered. Also, the position of the center of pressure was analyzed at various velocities of the nonturbulent flow. The calculation was carried out at the cruising altitude of a medium-range aircraft of 11 km. For the calculations, we used the characteristics of the air temperature, the pressure of a given height from the table of the standard atmosphere.

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