Science in China Series G: Physics, Mechanics & Astronomy © 2009 SCIENCE IN CHINA PRESS Springer-Verlag www.scichina.com phys.scichina.com www.springerlink.com Large eddy simulation of compressible turbulent channel flow with spanwise wall oscillation FANG Jian 1† , LU LiPeng 1 & SHAO Liang 2 1 National Key Laboratory on Aero-engines, School of Jet Propulsion, Beihang University, Beijing 100191, China; 2 Laboratory of Fluid Mechanics and Acoustics, Ecole Centrale de Lyon, France The influences of the modification of turbulent coherent structures on temperature field and heat transfer in turbulent channel flow are studied using large eddy simulation (LES) of compressible tur- bulent channel flows with spanwise wall oscillation (SWO). The reliability of the LES on such problems is proved by the comparisons of the drag reduction data with those of other researches. The high con- sistency of coherent velocity structures and temperature structures is found based on the analyses of the turbulent flow field. When the coherent velocity structures are suppressed, the transportations of momentum and heat are reduced simultaneously, demonstrating the same trend. This shows that the turbulent coherent structures have the same effects on the transportations of momentum and heat. The averaged wall heat flux can be reduced with appropriate oscillating parameters. large eddy simulation, spanwise wall oscillation, compressible, temperature field, heat transportation The spanwise wall oscillation (SWO) is an effective drag reducing technique to suppress turbulence activity. It was first studied in 1992 by Jung et al. [1,2] , who got the continual reductions of drag (40% the maximum), tur- bulence intensity and density of coherent structures. Af- ter the work of Jung [1,2] , Laadhari et al. [3] carried out the experimental research on the problem in the water channel, and validated the conclusions of Jung [1,2] . After that, lots of researchers carried out the numerical (Baron et al. [4] , Orlandi et al. [5] , Dhanak et al. [6] , Quadrio et al. [7] , Choi et al. [8] , Huang et al. [9,10] , Quadrio et al. [11] , Zhou et al. [12] , Riccoa et al. [13] ) and experimental (Trujillo et al. [14] , Choi et al. [15－18] , Cicca et al. [19] , Iuso et al. [20] , Ricco et al. [21] ) researches on this problem, and they came to the consistent results with those of Jung et al. [1,2] . Among them, Orlandi et al. [5] , Quadrio et al. [7] and Choi et al. [16] carried out the numerical and experimental re- searches on the pipe flow oscillating around its axis. The maximum drag reduction of 25% and some similar re- sults as in channel flows were reached. The SWO has drawn so much attention in recent decades, due to the dramatic drag reduction as a large scale control technique (the maximum drag reduction of 45% can be reached according to Choi et al. [15] , contras- tively, the riblets can only reach the level of 10%) and the connections with the dynamic mechanisms of self-sustaining process and regeneration of turbulence. Choi et al. [15] figured that, the reduction of drag was mainly caused by the negative spanwise vorticity in the near wall region which was generated by the interaction between streamwise vortex and induced Stokes layer by SWO. They also observed the distortion of streaks in the flow with oscillating wall. However, Baron et al. [4] and Dhanak et al. [6] figured out that the mechanism of the drag reduction was the movement of low-speed streaks related to the longitudinal vortices, which disturbed the spatial coherence between the longitudinal vortices and the low-speed streaks, and caused the weakening of the streaks. Based on the turbulence regeneration mecha- Received September 9, 2008; accepted November 10, 2008 doi: 10.1007/s11433-009-0165-3 † Corresponding author (email: fangjian@sjp.buaa.edu.cn) Supported by the Key Subjects of National Natural Science Foundation of China (Grant No. 10732090), the National Natural Science Foundation of China (Grant No. 50476004), and the 111 Project (Grant No. B08009) Sci China Ser G-Phys Mech Astron | Aug. 2009 | vol. 52 | no. 8 | 1233-1243