DRAG REDUCTION PREDICTION OF AHMED MODEL WITH TRAVELING WAVE BASED ON BP NEURAL NETWORK
|
Xingjun Hu , Jinglong Zhang , Yufei Luo , Jingyu Wang , Pengzhan Ma , Wei Lan , Chunbo Dong |
State Key Laboratory of Automotive Simulation and Control, Jilin University |
|
|
|
|
ABSTRACT |
n this paper, a traveling wave model is proposed to explore its influence on the aerodynamic drag of a Ahmed
model, the experimental and numerical results of aerodynamic drag coefficient CD for the Ahmed model are in good
agreement. Then by defining the aerodynamic benefit coefficient ΔCD as the evaluation index for the orthogonal experiment,
range analysis is conducted to determine the influences of the amplitude A, wavelength λ and frequency ω of the wave and
the vehicle speed u on ΔCD. After the analysis it can been found that λ has the least importance among these parameters,
hence A, ω and u are used to construct the 105 samples for training the BP neural network to predict ΔCD, results show that
ΔCD obtained from the neural network is significantly affected by the parameters of traveling wave. The prediction accuracy
of the network is furtherly verified by another 15 samples which are also built on A, ω and u, and the corresponding data
overlap rate of ΔCD is 96 %, so it can be concluded that the BP neural network constructed in this paper is accurate enough to
predict ΔCD. |
Key Words:
Ahmed model, Traveling wave model, BP neural networks, Drag reduction prediction
|
|