Journal of South China University of Technology (Natural Science Edition) ›› 2014, Vol. 42 ›› Issue (9): 140-146.doi: 10.3969/j.issn.1000-565X.2014.09.024

• Automotive Engineering • Previous Articles    

Simulation and Experimental Research on Performance of Decompression Engine Brake

Gong Jin- ke Wang Yun- ke Jia Guo- hai   

  1. State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body,Hunan University,Changsha 410082,Hunan,China
  • Received:2014-03-24 Revised:2014-07-30 Online:2014-09-25 Published:2014-08-01
  • Contact: 龚金科(1954-)，男，教授，博士生导师，主要从事动力机械新技术研究． E-mail:gongjinke@126.com
  • About author:龚金科(1954-)，男，教授，博士生导师，主要从事动力机械新技术研究．
  • Supported by:

    国家自然科学基金资助项目(51276056);湖南大学汽车车身先进设计制造国家重点实验室自主课题(61075002)

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Abstract:

In order to investigate the decompression engine brake performance,a mesh model is established withthe help of the software CFD (Computational Fluid Dynamics) according to the analysis on its working process.Then,a 3D simulation of the working process of the transient decompression engine brake is performed by means ofthe dynamic mesh technology,and the simulation results are verified by experiments.The results show that (1) thehigher the rotating speed of engine is,the better its braking performance will be; (2) the larger the decompressionvalve opening is,the higher the brake power peak will be; (3) however,the maximum decompression valve openingis limited by compression clearances and piston movement rules; and (4) at a certain rotating speed,each decom-pression valve opening corresponds to an optimal decompression valve advance angle,which causes an optimal bra-king performance.Besides,the optimal valve advance angle decreases as the decompression valve opening increases.

Key words: engines, decompression brake, computational fluid dynamics, dynamic mesh technology, numerical simulation

CLC Number: