本论文利用直授数值模拟建立了槽退湍流的数据库。数值计算方法采用谱方法，时间积分采用具有三阶精度的时间分裂格式。利用影响系数矩阵进行散度修正，在流向和展向来用3l2．规则消除混淆误差。计算的雷诺数Re，＝173，建立的数据库资源如下：在直槽4zdyx2Hx2zdy区域内的128x129x128个网格点上，存有200时间步的速度压力场。 对此数据库进行统计分析，计算包括速度脉动的两点相关系数、一雏能谱、平均速度剖面、脉动速度和压力的均万根剖面、雷诺应力剖面、脉动涡量的均方根剖面、倔斜因子和光滑因子等。这些统计结果与Kim，Moin＆Moser（tesv）的结果符合得很好，表明本数据库是可靠的。 利用此数据库对雷诺应力输运万程和耗散率万程进行了平衡分析，为湍流模型的评价与改进建立了基础。对霓诺应力摸式进行评价，并提出了改进意见。分析了对e一方程的模拟结果，并对小涡拉伸产生项和粘性破坏项提出了改进模型，大力提高了近壁区模拟的准确度。 利用此数据库对近壁湍流的相干结构进行了研究。通过再现壁湍流中典型的相于结构，对条带结构、狩发过程和涡结构在湍流产生与维持中的重要作用加以肯定，并提出了尚需进一步研究的问题。对首次发现的层流底层横向速度的强脉冲现象进行了仔细的研究，描述了强脉冲事件的一般沸灾剩⒎治隽说ジ鍪录鞒〉目占浣峁埂Ｑ芯拷峁砻鳎庵智柯龀逑窒笤谕牧鞯牟胛种衅鹱胖匾饔茫墙谕牧髯晕只频闹匾录□

The database of fully developed turbulent channel flow is set up through direct numerical simulations. The spectral methods employing Fourier series and Chebyshev polynomials are used to complete the spatial discretization and the time-splitting method with third-order time-accuracy is adopted to carry out time advancement. The influence coefficient matrix is employed to eliminate the residual divergence caused by time splitting method. The aliasing errors are removed in streamwise and spanwise directions by spectral truncation method (also referred to as 3/2-rule).The Reynolds number is Reτ=173(based on channel half width and wall shear velocity).The resource of the database is as the following: 200 velocity-pressure fields with the resolution of 128 x 129 x 128 are stored in the domain with the dimension of 4πH x 2H x 2πH. Some statistical results of the database are presented, such as two-point correlation coefficients of velocity fluctuations, one-dimensional energy spectra, mean velocity profile, root-mean-square of velocity, pressure and vorticity fluctuations, Reynolds shear stress, skewness factors and flatness factors. All these results are compared with the results of Kim, Moin & Moser(1987) and the good agreement confirms the reliability of the database. Using the database, the balance equations of Reynolds shear stresses and the dissipation rate are analyzed. The Reynolds stress models are evaluated. The models of the equation of the dissipation rate are studied. A new model of the production and viscous destruction terms of turbulence dissipation is given and it makes a great improvement in the near-wall behavior. The turbulent coherent structures in the near-wall region are studied. The typical structures of wall turbulence such as low-speed streaks, bursting events and vortical structures are presented. Their importance to turbulence production are confirmed. The high kurtosis levels of transverse velocity fluctuation in laminar sublayer are found and studied for the first time. Their general properties are described and the structures of the velocity fields of the chosen sample are analyzed. Our studies indicate that the events with high kurtosis levels of transverse velocity fluctuation in laminar sublayer are very important to turbulence production and they are the important events of self- generating mechanism of turbulence in the near-wall region. The high kurtosis levels of transverse velocity fluctuation has been confirmed by an experiment. Key words: turbulence, direct numerical simulation, coherent structures.