scholarly journals Influence of Side Spoilers on the Aerodynamic Properties of a Sports Car

Energies ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4697
Author(s):  
Krzysztof Kurec ◽  
Janusz Piechna
Keyword(s):  
Load Distribution ◽  
Aerodynamic Drag ◽  
Numerical Calculations ◽  
Aerodynamic Load ◽  
Aerodynamic Forces ◽  
Side Force ◽  
Aerodynamic Properties ◽  
Drag And Lift ◽  
Yaw Angle

This paper discusses the capabilities of side spoilers to improve the aerodynamic properties of a sports car exposed to a non-zero yaw angle flow. In such conditions, the aerodynamic drag and lift both increase with the introduction of a side force and a yawing moment, which contribute to the decrease of the car’s handling properties and force the car to change its driving path. Elements mounted on the side of the car make it possible to obtain an asymmetric aerodynamic load distribution and generate additional forces that can be used to counter these effects. The performance of the side spoilers was analyzed at yaw angles ranging from 0° to 15° using the results of numerical calculations. It was established that the side spoilers made it possible to generate at low yaw angles aerodynamic forces that exceeded those caused by a crosswind.

CFD study of aerodynamic performance of non-pneumatic tyre with hexagonal spokes

2021 ◽  
pp. 095440702110131
Author(s):  
Daksh Bhatia ◽  
Praneeth KR ◽  
Babu Rao Ponangi ◽  
Meghana Athadkar ◽  
Carine V Dsouza
Keyword(s):  
Comparative Study ◽  
Lift Coefficient ◽  
Aerodynamic Performance ◽  
Practical Implementation ◽  
Air Velocity ◽  
Aerodynamic Forces ◽  
Steering Angle ◽  
Camber Angle ◽  
Drag And Lift ◽  
Yaw Angle

Non-pneumatic tyres (NPT) provide a greater advantage over the pneumatic type owing to their construct which increases the reliability of the tyre operation and effectively reduces maintenance involved. Analysing the aerodynamic forces acting on a NPT becomes a crucial factor in understanding it’s suitability for practical implementation. In the present work, the aerodynamic performance of a NPT using CFD tool – SimScale® is studied. This work includes a comparative study of a pneumatic tyre, a NPT with wedge spokes and a NPT with hexagonal spokes (NPT-HS). The effect of air velocity, steering (yaw) angle and camber angle on the aerodynamic performance of the NPT-HS is evaluated using CFD. By increasing the steering angle from 0° to 15°, the lift coefficient decreases by 37% approximately at all velocities. Whereas drag coefficient initially decreases by 21% till 7.5° steering angle and then starts increasing. Increasing camber angle from 0° to 1.5°, both drag and lift coefficients goes on decreasing by approximately 7% and 27% respectively.

CFD Analysis of Drag Reduction Using External Devices on Pickup Trucks

2010 ◽  
Author(s):  
Feysal A. Adem ◽  
Dongmei Zhou ◽  
Pramod Krishnani
Keyword(s):  
Numerical Simulations ◽  
Inclination Angle ◽  
Cfd Simulation ◽  
Aerodynamic Drag ◽  
Lift Coefficient ◽  
Aerodynamic Drag Coefficient ◽  
Zero Degree ◽  
Drag And Lift ◽  
Drag And Lift Coefficient ◽  
Yaw Angle

The flows over a pickup truck with add-on devises were studied using computational fluid dynamics (CFD) with the objective of investigating the effect of these add-no devices on the flow structures around the vehicle, aerodynamic drag, and lift coefficient. All numerical simulations were performed using commercial CFD software Fluent [8]. A generic pickup model with extended cab was used as the base model and all the flow simulations were performed at zero degree yaw angle. The pickup configurations used in the present CFD simulation include Aerocap with different rear inclination angle α, Tonneau cover, Rear Roof Garnish, and Tail-plates. Results from numerical simulations indicated that Aerocap with inclination angle α = 12° and a reduced rear width has produced the minimum aerodynamic drag coefficient. It was also shown that the wake region decrease when the rear inclination angle increases.

A Study of caravan unsteady aerodynamics

2003 ◽  
Vol 217 (7) ◽  
pp. 551-560 ◽  
Author(s):  
J Darling ◽  
P M Staden
Keyword(s):  
High Speed ◽  
Unsteady Aerodynamics ◽  
Aerodynamic Forces ◽  
Side Force ◽  
Aerodynamic Damping ◽  
Novel Technique ◽  
Handling Characteristics ◽  
Aerodynamic Properties ◽  
Scale Models ◽  
Speed Stability

The high speed stability and handling characteristics of car-trailer combinations are affected by both road and aerodynamic forces. While the tyre-to-road interaction is well understood the action of gusts, passing large vehicles and even small steering inputs will disturb the symmetry of flow and generate aerodynamic forces and moments which are suffcient to affect the handling of the system. Although accidents caused by high speed instability are relatively uncommon a better understanding of these aerodynamic effects will improve safety. In this paper a series of wind tunnel investigations using scale models are presented. Steady state investigations were used to measure the aerodynamic properties of the car-caravan pair while a novel technique was developed to measure the aerodynamic damping derivatives in yaw and side force for a caravan model. These damping derivatives were shown to be destabilizing in most cases of sideslip and stabilizing in yaw although it was demonstrated that high damping derivatives were attained at certain frequencies of excitation.

On the Theory of the Calculation of the Constant Velocity Ball Transmission Joints

1976 ◽  
Vol 98 (3) ◽  
pp. 852-857 ◽  
Author(s):  
N. Bellomo
Keyword(s):  
Working Conditions ◽  
Load Distribution ◽  
Constant Velocity ◽  
Numerical Calculations ◽  
Torque Capacity ◽  
Safe Working ◽  
General Method

In this work a general method for the calculation of constant velocity ball transmission joint with straight grooves is studied. Numerical calculations concerning the forces transmitted by each driving ball and the torque capacity have been realized with reference to known and manufactured types of joint. The study allows one to deduce some important and experimentally confirmed designing rules and gives a precise picture of the load distribution in the joint as well as the limits of safe working conditions.

Unsteady Aerodynamic Forces Measured on a Fluttering Profile

2014 ◽  
Author(s):  
Igor Zolotarev ◽  
Václav Vlček ◽  
Jan Kozánek
Keyword(s):  
Mach Number ◽  
Flow Field ◽  
Degrees Of Freedom ◽  
Air Flow ◽  
Optical Measurements ◽  
Energy Contribution ◽  
Aerodynamic Forces ◽  
Unsteady Aerodynamic ◽  
New Information ◽  
Drag And Lift

The study presents evaluation of optical measurements of the air flow field near the fluttering profile NACA0015 with two-degrees of freedom, Mach number of the flutter occurrence were M=0.21 and M=0.45. Aerodynamic forces (drag and lift components) were evaluated independently on the upper and lower surfaces of the profile. Using the mentioned decomposition, the new information about mechanism of flutter properties was obtained. The forces on the upper and lower surfaces are phase shifted and are partially eliminated as a result of the circulation around the profile. The cycle changes of these forces cause the permanent energy contribution from the airflow to the vibrating system.

scholarly journals Bearing friction effect on cup anemometer performance modelling

2021 ◽  
Vol 2090 (1) ◽  
pp. 012101
Author(s):  
D Alfonso-Corcuera ◽  
S. Pindado ◽  
M Ogueta-Gutiérrez ◽  
A Sanz-Andrés
Keyword(s):  
Rotation Rate ◽  
Aerodynamic Drag ◽  
Aerodynamic Characteristics ◽  
Friction Torque ◽  
Performance Modelling ◽  
Friction Forces ◽  
Aerodynamic Drag Coefficient ◽  
Yaw Angle ◽  
Cup Anemometer ◽  
Bearing Friction

Abstract In the present work, the effect of the friction forces at bearings on cup anemometer performance is studied. The study is based on the classical analytical approach to cup anemometer performance (2-cup model), used in the analysis by Schrenk (1929) and Wyngaard (1981). The friction torque dependence on temperature was modelled using exponential functions fitted to the experimental results from RISØ report #1348 by Pedersen (2003). Results indicate a logical poorer performance (in terms of a lower rotation speed at the same wind velocity), with an increase of the friction. However, this decrease of the performance is affected by the aerodynamic characteristics of the cups. More precisely, results indicate that the effect of the friction is modified depending on the ratio between the maximum value of the aerodynamic drag coefficient (at 0° yaw angle) and the minimum one (at 180° yaw angle). This reveals as a possible way to increase the efficiency of the cup anemometer rotors. Besides, if the friction torque is included in the equations, a noticeable deviation of the rotation rate (0.5-1% with regard to the expected rotation rate without considering friction) is found for low temperatures.

scholarly journals Estimation of Aerodynamic Load on Radome Structure Mounted on Top of a Surveillance Aircraft

2020 ◽  
Vol 9 (3) ◽  
pp. 1969-1973
Keyword(s):  
Wind Tunnel ◽  
Pressure Distribution ◽  
Structural Design ◽  
Pressure Transducer ◽  
Dorsal Side ◽  
Aerodynamic Load ◽  
Aerodynamic Forces ◽  
Support Structure ◽  
Aerodynamic Angles ◽  
Valve Pressure

The design and development of radome external structure, requires aerodynamic forces acting on it and its distribution. This paper discusses the wind tunnel studies carried out for estimating the incremental effects due to the installation of large ellipsoidal radome along with the support structure pylons on the dorsal side of the fuselage. Effect of locations of radome at 36 m and 31.5 m from the nose of the fuselage is discussed. Further using the scan-valve pressure transducer, the pressure distribution on the radome measured at different aerodynamic angles required for the structural design of radome structure is also brought out. Flow visualization study which are useful for qualitative check for the effect of installation of the radome with support structure on the effectiveness of the empennage is attempted.

scholarly journals Numerical studies on aerodynamics of high-speed railway train subjected to strong crosswind

2019 ◽  
Vol 11 (11) ◽  
pp. 168781401988727
Author(s):  
Xu Wang ◽  
Yuanhao Qian ◽  
Zengshun Chen ◽  
Xiao Zhou ◽  
Huaqiang Li ◽  
...  
Keyword(s):  
Wind Speed ◽  
High Speed ◽  
Lift Coefficient ◽  
Aerodynamic Characteristics ◽  
Width Ratio ◽  
Force Coefficient ◽  
Rolling Moment ◽  
Side Force ◽  
Train Speed ◽  
Yaw Angle

Under the action of strong crosswind, the aerodynamic behavior of a rail vehicle at high speed will be changed significantly, which could directly affect the safe operation of the vehicle. With the help of the shape of train used in China, the aerodynamic characteristics of trains with scale of 1:1 is investigated using computational fluid dynamics numerical simulation method, which consists of the variation of aerodynamics force and moment with wind yaw angle, wind speed, train speed, and nose shape. After an initial validation against Baker’s results from wind tunnel test, the numerical model is then used to investigate the aerodynamic characteristics of the trains. The numerical results indicate that lift coefficient of the M train is slightly higher than TMC1 and TMC2 trains. Regardless of aerodynamics force coefficients, TMC1 reaches the maximum at a yaw angle of 75°. Aerodynamics force coefficient increases with both wind speed and train speed, but the change of which is not linear. Comparing aerodynamic force with different geometric dimensions of train nose, it is shown that height–width ratio is insensitive to side force and rolling moment, but sensitive to lift force from the yaw angle 0°–90°. The side force coefficient, as we most concern, is less than other results, when the length–width ratio is 1 and height–width is 0.87.

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
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