Zou et al. / J Zhejiang Univ Sci A 2007 8(7):1053-1058 1053 Simulation of turbulent combustion in DLR Scramjet * ZOU Jian-feng † , ZHENG Yao, LIU Ou-zi †‡ (School of Aeronautics and Astronautics, Zhejiang University, Hangzhou 310027, China) † E-mail: zoujianfeng@zju.edu.cn; liuouzi@hotmail.com Received Feb. 10, 2007; revision accepted Apr. 17, 2007 Abstract: Turbulent combustion in a DLR (German Aerospace Center) Scramjet engine was simulated using the newly-proposed Partially Resolved Numerical Simulation (PRNS) procedure. The PRNS procedure uses temporal filtering to define large-scale turbulence, and the model developed to account for unresolved scales is grid independent. No problem about inner commutation error and inconsistencies will arise from the PRNS, while such issues are of concern in traditional Large Eddy Simulation (LES) methods. The mean results have good agreement with the experiment data and the flow structures with small scales are well resolved. Key words: Scramjet, Turbulent combustion, Unstructured grid, Finite volume method doi:10.1631/jzus.2007.A1053 Document code: A CLC number: O35 INTRODUCTION An increasing research effort has been made to investigate high speed turbulent combustion nu- merically, which is resulted from the interests in hypersonic air breathing propulsion. A serious issue about turbulent combustion is the simulation of turbulence with multi-scale feature. For the traditional Large Eddy Simulation (LES) or hybrid RANS/LES approaches (Spalart et al., 1997; Bush and Mani, 2001; Fan et al., 2001; Georgiadis et al., 2001; Menter et al., 2003; Nichols and Nelson, 2001; Strelets, 2001), spatially filtered equations are used to compute the resolved scales of turbulence and certain sub-grid models for unresolved scales. There are several drawbacks associated with the spa- tially filtered equations and sub-grid models, which are stated by Shih and Liu (2004; 2005), i.e. the in- consistency between the filter function and sub-grid models, the commutation error due to the non-uni- form computational mesh, the grid-dependent solu- grid-dependent solution, and the effect of numerical dissipation introduced by higher- order schemes. Shih and Liu (2004; 2005) proposed a new methodology of Partially Resolved Numerical Simu- lation (PRNS) based on temporal filtering and dem- onstrated that, with the so-called “resolution control parameter”, one can carry out a unified simulation from RANS towards LES or vise versa. This meth- odology does not involve spatial filtering, and there will be no issues about commutation errors, incon- sistencies between the filter and sub-grid scale mod- els, etc. Shih and Liu (2004; 2005) have computed the turbulent flow for pipe flow and LM6000 combustor with the preliminary results being encouraging. Cai and Ladeinde (2006) provided their evaluation on the PRNS procedure for near-wall turbulence prediction. In the present study, the PRNS will be coupled with our own combustion code, which is expected to present a more encouraging and accurate description for turbulence in the Scramjet engine. The turbulence in the DLR Scramjet engine is investigated with our combustion code. The avail- able numerical and experimental data for DLR Scramjet engine was presented by Oevermann (2000) and used for benchmark. Our work will focus on Journal of Zhejiang University SCIENCE A ISSN 1673-565X (Print); ISSN 1862-1775 (Online) www.zju.edu.cn/jzus; www.springerlink.com E-mail: jzus@zju.edu.cn ‡ Corresponding author * Project supported by the National Natural Science Foundation of China (No. 90405003), and the China Postdoctoral Science Founda- tion (No. 20060390339)