Service Solution Success

Aerodynamic Performance Analysis

Purpose  

     Through the aerodynamic performance analysis , the flow pattern around vehicle is better understood. The following objectives will be achieved:

1Reduction of fuel consumption Drag analysis

2Improvement of driving stability Lift analysis

Driving stability Example: Passing a sharp bend, the car is more secure under the positive pitch moment.

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      Understeering : Lift Balance CLF > CLR         Oversteering : Lift Balance CLF < CLR        

        Positive Pitch Moment : Stable Negative Pitch Moment : Unstable

Assessment

After the aerodynamic performance evaluation of the local flow field, a targeted optimal design is carried out. For example: An air pressure diversion optimization of the front wheel is necessary because of the pressure increment caused by air collision in the front tire.

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Flow around the front wheels

Parametric study

Through the analysis of the design parameters of the body shape and aerodynamic components , improve the aerodynamic performance of the car. For example:

Influence of ground clearance on drag coefficient

 

Base model

Ground clearance (10mm downward)

Shape

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Parameter analysis

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Optimization parameter

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-

Cd

Confidential

0.002

Influence of engine room undercover shape on drag coefficient

 

Base model

Shape of engine room undercover

Undercover length (Improvement 1)

Undercover length (Improvement 2)

Shape

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Flow pattern

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Cd

Confidential

0.009

0.012

 

Optimization

a) Chassis optimization

Through the chassis optimization, drag coefficient is decreased by 0.032, and coolant temperature by 4. Aerodynamic performance and engine room cooling performance are improved.

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Figure Optimization model and flow chart

 

b)Bumper layout optimization

The location of the bumper is parameterized by overset function, and the distribution of the optimal solution is calculated. The best optimized solution has a minimum CD and a maximum negative CL,  i.e the solid red dot in the figure.

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Bumper Layout

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Bumper Layout optimization results

Vehicle passing stability analysis

Test mode

Sedan(80KPH) / Bus(120KPH). An analysis of the car driving stability when a bus is overtaking it is made.

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Analysis result

    The maximum side force occurs in the 1.5s after the bus overtaking it.

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Lift coefficient

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Yaw moment coefficient

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Experiences

1)       Drag coefficient analysis of various vehicles

2)       Analysis of lift balance and driving stability

3)Dust cover, wheel and chassis layout design

4)Design optimization of rear vortex generator

5)Development of vehicle aerodynamic performance and cooling performance 

6)Design optimization of roof visor for commercial vehicle

7)Development of integrated platform for fuel cell vehicle

8)Shape design of SUVs on aerodynamic performance optimization

9)Development of virtual wind tunnel for aerodynamic analysis

Engineering service

Aerodynamic Performance Analysis