Abstract

A dynamic Smagorinsky–Lilly model (DSLM) subgrid model on the basis of the Smagorinsky–Lilly subgrid model (SLM) was introduced in the OpenFOAM software. The flow field of the vehicle was simulated, and the pressure coefficient and sound pressure curve of the monitoring points were compared with the wind tunnel test results. The results show that the DSLM subgrid model with a wall function can achieve high simulation accuracy. The investigation of the flow field structure revealed an intermittent detachment of the turbulent vortex after the airflow passed through the rearview mirror, thereby resulting in a violent pressure pulsation on the side window around the rearview mirror. Airflow passed through the A-pillar, separated, and reattached on the upper side window, thereby producing aerodynamic noise. The research results can serve as a good reference for the simulation and test of aerodynamic noises outside the vehicle, and for the reduction of the aerodynamic noises of vehicles.

Highlights

  • Passenger comfort has become increasingly important along with improvements in automobile performance and increasing consumer demands

  • The results showed that the intensity of the aerodynamic noise source in the optimized rear side window surface weakens in each frequency band, and the sound pressure level of each monitoring point is reduced

  • The current study aims to explore the applicability of large eddy simulation (LES) in predicting the exterior vehicle aerodynamic noise and its influence on the simulation precision

Read more

Summary

Introduction

Passenger comfort has become increasingly important along with improvements in automobile performance and increasing consumer demands. Experimental simulation measures the pressure fluctuation or noise value of a target area through road and wind tunnel tests or by capturing the structure of the flow field and analyzing the relationship between flow and aerodynamic noise [5,6]. The calculation results of LES with wall function and subgrid model approximate those obtained using the wind tunnel test, the influence of the aerodynamic noise on the simulation precision is not considered. This study uses the OpenFOAM platform in applying LES with wall function to simulate the automobile external flow field, and obtain and compare the pressure coefficient and curve of the sound pressure level with those determined using the wind tunnel test. This research summarizes the influence of LES with different subgrid models on the precision of car exterior aerodynamic noise simulations, and explores the noise generation mechanism on the side window around the rearview mirror

Computational Theory
SLM Subgrid Model
Dynamic SLM Ssubgrid Mmodel
Lij Sij
Acoustic Analogy Method Based on the Ffowcs Williams-Hawkings Equation
The Experimental Introduction
Surface
Background
Simulation
Geometrical
Computational
11. Boundary
Boundary Condition
Transient Solution Settings
Results of of Flow
14. Pressure
15. Pressure
Analysis of the Sound Field
16. Comparison
Analysis of Simulation Results
20. Velocity
Conclusions
Conclusion
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call