Coupled Analysis of Unsteady Aerodynamics and Vehicle Motion of a Heavy Duty Truck in Wind Gusts

2010 ◽  
Author(s):  
Takuji Nakashima ◽  
Makoto Tsubokura ◽  
Takeshi Ikenaga ◽  
Kozo Kitoh ◽  
Yasuaki Doi
Keyword(s):  
Vehicle Dynamics ◽  
Unsteady Aerodynamics ◽  
Dynamics Simulation ◽  
Coupled Analysis ◽  
Wind Gust ◽  
Strong Wind ◽  
Heavy Duty ◽  
Aerodynamic Forces ◽  
Heavy Duty Truck ◽  
Unsteady Aerodynamic

In the present study, unsteady aerodynamic forces acting on a simplified heavy duty truck in strong wind gust and their effects on the truck’s motion were investigated by using a coupled analysis. Unsteady fluid dynamics simulation was applied to numerically reproduce unsteady aerodynamic forces acting on the truck under sudden crosswind condition. Taking account of vehicle’s motion, moving boundary techniques were introduced. Motions of the truck were simulated by a vehicle dynamics simulation including a driver’s reaction. The equations of motion of the truck in longitudinal, lateral, and yaw-rotational directions were numerically solved. These aerodynamics and vehicle dynamics simulations were coupled by exchanging the aerodynamic forces and the vehicle’s motion. In order to investigate effects of the unsteady vehicle aerodynamics on the vehicle’s motion, conventional analysis of the vehicle’s motion using quasi-steady aerodynamic forces and one-way coupled analysis with fixed vehicle attitude were also conducted. The numerical results of these simulations were compared with each other, and the effects of the two kinds of unsteady aerodynamics were discussed separately and totally. In the sudden crosswind condition, the unsteady aerodynamics effected significantly on the truck’s motion. An effect of transient aerodynamics as the truck ran into a sudden crosswind was greater than an effect of unsteady aerodynamics caused by unsteady vehicle’s motion, while both of the effects showed significance.

Unsteady Aerodynamics Simulation of a Heavy-Duty Truck in Wind Gusts Coupled With Vehicle Motion Analysis in Six Degrees of Freedom

2011 ◽  
Author(s):  
Takuji Nakashima ◽  
Makoto Tsubokura ◽  
Syumei Matsuda ◽  
Yasuaki Doi
Keyword(s):  
Vehicle Dynamics ◽  
Degrees Of Freedom ◽  
Vertical Direction ◽  
Dynamics Simulation ◽  
Strong Wind ◽  
Heavy Duty ◽  
Aerodynamic Forces ◽  
Six Degrees Of Freedom ◽  
Heavy Duty Truck ◽  
Wind Gusts

A one-way coupled analysis was used to investigate both the unsteady aerodynamic forces on a simplified heavy-duty truck in strong wind gusts and their effects on its motion. The vehicle model for the dynamics simulation was extended to six degrees of freedom (6DoF). First, a transitional aerodynamics simulation was conducted for the simplified truck with a fixed vehicle attitude but subject to a sudden crosswind. Based on the visualized results of this aerodynamics simulation, flow phenomena generating transitional aerodynamic forces and moments are discussed, especially those acting in the vertical direction. While the truck was running into the crosswind region, the growth and breakdown of a large-scale vortex above the container generated a transitional behavior of aerodynamic lift and pitching moment. Next, time series of the six components of the aerodynamic forces and moments were input into the vehicle dynamics simulation. By comparing the results with those of a quasi-steady aerodynamics simulation, the effect of transitional aerodynamics on vertical motions was clarified, with the largest difference found in a rolling motion. Moreover, the effect of considering 6DoF was investigated by also conducting the vehicle dynamics simulation with 3DoF. The consideration of dynamics in the vertical direction changed the estimation of tire forces, which were related to a vertical load on the tire. Finally, the effects of considering 6DoF were also identified for horizontal motions.

Large Eddy Simulation on the Unsteady Aerodynamics of a Heavy Duty Truck in Wind Gust

2011 ◽  
Author(s):  
Makoto Tsubokura ◽  
Prasanjit Das ◽  
Tomofuyu Matsuuki ◽  
Takuji Nakashima
Keyword(s):  
Large Eddy Simulation ◽  
Numerical Method ◽  
Unsteady Aerodynamics ◽  
Static Condition ◽  
Wind Tunnels ◽  
Wind Gust ◽  
Heavy Duty ◽  
Heavy Duty Truck ◽  
Eddy Simulation ◽  
Large Eddy

Unsteady aerodynamic forces acting on a full-scale heavy duty truck were investigated using a large-eddy simulation technique. The numerical method adopted was first validated on a static condition measured at the DNW German-Dutch wind tunnels. After the correction of the blockage ratio in the wind tunnel, the drag coefficient obtained by our numerical method showed good agreement with the experimental data within the errors of less than 5%. Effect of an air deflector mounted on the top of a cabin was also discussed. Then the method was applied to non-stationary conditions in which the truck was subjected to ambient perturbation of approaching flow. The perturbation of the flow is a model of atmospheric turbulence and sinusoidal crosswind velocity profiles were imposed on the uniform incoming flow with its wavelength comparable to the vehicle length. As a result, it was confirmed that when the wavelength of the crosswind is close to the vehicle length, averaged drag increases by more than 10% and down-force decreases by about 60%, compared with the case without perturbation.

HPC-LES for Unsteady Aerodynamics of a Heavy Duty Truck in Wind Gust - 1st report: Validation and Unsteady Flow Structures

2010 ◽  
Author(s):  
Makoto Tsubokura ◽  
Kaito Takahashi ◽  
Tomofuyu Matsuuki ◽  
Takuji Nakashima ◽  
Takeshi Ikenaga ◽  
...  
Keyword(s):  
Unsteady Flow ◽  
Unsteady Aerodynamics ◽  
Flow Structures ◽  
Wind Gust ◽  
Heavy Duty ◽  
Heavy Duty Truck

On the Unsteady Aerodynamic Forces Acting on a Formula Car in a Wind Gust

2009 ◽  
Author(s):  
Makoto Tsubokura ◽  
Takuji Nakashima ◽  
Yoshihiro Sasaki ◽  
Kozo Kitoh
Keyword(s):  
Wind Gust ◽  
Aerodynamic Forces ◽  
Unsteady Aerodynamic

Coupled analysis of the unsteady aerodynamics and multi-body dynamics of a small car overtaking a coach

2019 ◽  
Vol 233 (14) ◽  
pp. 3684-3699 ◽  
Author(s):  
Jun Liu ◽  
Zhengqi Gu ◽  
Taiming Huang ◽  
Shuya Li ◽  
Ledian Zheng ◽  
...  
Keyword(s):  
Adverse Effect ◽  
Unsteady Aerodynamics ◽  
Coupled Analysis ◽  
Detached Eddy Simulation ◽  
Aerodynamic Loads ◽  
Unsteady Aerodynamic ◽  
Eddy Simulation ◽  
Body Dynamics ◽  
Vehicle Motion ◽  
Multi Body

The severe additional aerodynamic loads that are generated on a small car when overtaking a coach have an adverse effect on the car handling stability and its safety. In this article, a two-way coupling of the unsteady aerodynamics and multi-body dynamics is performed in order to study the mutual interactions of a car in an overtaking maneuver with a coach. The unsteady aerodynamic interactions are obtained by using SST (Menter) K-Omega Detached Eddy Simulation and overset mesh technology. The aerodynamics couple the multi-body dynamics, taking into account the effects of the transverse spacing and the cross winds. To validate the necessity of the two-way coupling method, a one-way coupling of the aerodynamics to the vehicle motion is also conducted. Finally, by comparing the aerodynamic loads and the dynamic response of the overtaking car in different overtaking maneuvers between one- and two-way coupling, the results show that it should be considered with two-way coupling analyses of the car while overtaking a coach, particularly under the severe conditions of a lower transverse spacing or the crosswinds.

Integration and Use of Diesel Engine, Driveline and Vehicle Dynamics Models for Heavy Duty Truck Simulation

1999 ◽  
Author(s):  
Dennis N. Assanis ◽  
Walter Bryzik ◽  
Nabil Chalhoub ◽  
Zoran S. Filipi ◽  
Naeim Henein ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Vehicle Dynamics ◽  
Heavy Duty ◽  
Heavy Duty Truck ◽  
Dynamics Models

A Free-Rolling Cornering Test for Heavy-Duty Truck Tires

1996 ◽  
Vol 24 (2) ◽  
pp. 153-180 ◽  
Author(s):  
M. G. Pottinger ◽  
W. Pelz ◽  
G. A. Tapia ◽  
C. B. Winkler
Keyword(s):  
Vehicle Dynamics ◽  
Task Force ◽  
Test Procedure ◽  
Heavy Duty ◽  
Heavy Duty Truck ◽  
Truck Tire ◽  
Truck Tires ◽  
Background Data ◽  
Dynamics Simulations ◽  
Future Work

Abstract Under the guidance of the SAE Truck Tire Characteristics Task Force, the background to support the creation of a recommended practice for experimentally determining the free-rolling cornering properties of heavy-duty truck tires has been developed. The value of such a recommended practice lies in the establishment of a broadly accepted procedure for obtaining the free-rolling cornering data needed to represent tires in vehicle dynamics simulations of commercial trucks. This paper presents the proposed test procedure and background data. It contains a summary of the proposed test procedure, example data from CALSPAN and UMTRI using the proposed procedure, a statistical comparison of the data from CALSPAN and UMTRI, a discussion of the effect of inflation pressure on the data, a discussion of how the proposed test affects tire cornering properties and tread surface topography, and a look at the projected future work of the task force.

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