Three-dimensional compressible fluid flow about an array of small diameter cylinders, on which oblique jets impinge.

摘要

Numerical simulation and laboratory experiments have been used synergistically to investigate the three-dimensional compressible flow about an array of small-diameter cylinders. The array was impinged by a pair of obliquely oriented slot jets. The jet impingement created a highly complex, turbulent flow field. In order to obtain an accurate numerical simulation of the flow, it is necessary to select an appropriate turbulence model. In the absence of prior work on the exact subject of interest here, the selection of the turbulence model was implemented by making use of a fluid flow situation which has some commonality to that being considered - the wall jet. Two manifestations of the wall jet were employed: the plane wall jet and the annular wall jet. Numerical predictions based on five well-established turbulence models were compared with available experimental data for the two wall jet versions. It was found that the k-epsilon with enhance wall treatment provided the best fit between the predictions and the data. Numerical simulations were carried out for both two-dimensional and three-dimensional models of the obliquely impinged small diameter cylinder. The two-dimensional case yielded information about the response of the shear exerted on the cylinder to variations of the point of the impingement. For the three-dimensional studies, the impingement point was fixed from the information obtained from the two-dimensional case. Numerical predictions were obtained for the three-dimensional case for the entire flow field. An experimental apparatus was set up to validate the predictions of the simulation, and good agreement with predictions occurred.