Velocity and concentration profiles in a pipe flow was measured downstream of injection of a tracer gas at the pipe centerline. The pipe had diameter D = 0.2 m and two Reynolds numbers, Re = 50000 and Re = 100000, were used. The profiles were measured at positions 5D and 10D downstream of the injection point. Three different industrial relevant geometrical configurations were used upstream of the injection point: a 10D straight pipe, two 10D pipes connected with a 90° bend or a straight 10D pipe with a mixer plate mounted 2D upstream the injection point. In all cases, air entered the pipe from the surroundings through a sharp-edged inlet. This represents many practical flow applications and is also a well-defined inlet condition that generates turbulence in the vena contracta in the inlet. The measurements were compared to predictions from three different computational models: two with Reynolds Averaged Navier-Stokes (RANS) and one with high-resolution Detached Eddy Simulation (DES). For RANS, the k-ω SST model had difficulty in predicting the turbulence created by the vena contracta. The k-ε model performed better, but gave completely wrong results for the inlet with a pipe bend. The DES was successful for all cases with only minor deviations from measurements.

在管道中心线注入示踪气体后，测量管道中的流速和浓度分布。管道的直径D = 0.2 m，并使用两个雷诺数Re = 50000和Re = 100000。在注入点下游的5 D和10 D位置测量轮廓。在注入点的上游使用了三种不同的与工业相关的几何构造：一条10 D直管，两条90°弯管连接的10 D管或一条装有2 D混合器板的直10 D管。注入点的上游。在所有情况下，空气都是通过锋利的进气口从周围环境进入管道的。这代表了许多实际的流动应用，并且也是定义明确的入口条件，在入口的腔静脉收缩中产生湍流。将测量结果与来自三种不同计算模型的预测结果进行了比较：两种模型具有雷诺平均纳维-斯托克斯（RANS），另一种具有高分辨率的分离涡模拟（DES）。对于RANS，在K- ω SST模型具有预测由产生的涡流难度缩。k- ε该模型的性能较好，但对于带有弯管的入口却给出了完全错误的结果。DES在所有情况下都是成功的，与测量值的偏差很小。