Issue |
Volume 7, 2015
Progress in Flight Physics – Volume 7
|
|
---|---|---|
Page(s) | 311 - 328 | |
Section | Jets and wakes | |
DOI | https://doi.org/10.1051/eucass/201507311 | |
Published online | 08 June 2015 |
Combined experimental and numerical investigation of a transonic space launcher wake
1
Institute of Fluid Mechanics and Aerodynamics Bundeswehr
University Munich
Munich,
Germany
2
Institute of Aerodynamics RWTH Aachen
University
Aachen,
Germany
Combined experimental und numerical investigations of the turbulent wake of a generic space launcher at transonic free stream conditions (Ma∞ = 0.7 and ReD = 1.0 · 106) are performed to gain a better understanding of intricate phenomena of the wake flow physics and to validate new methods for its analysis. The experiments are conducted at the Bundeswehr University Munich using a high-repetition-rate particle image velocimetry (PIV) system, while the numerical investigation is performed by the Institute of Aerodynamics of RWTH Aachen University using a zonal Reynolds-averaged Navier-Stokes (RANS) / large-eddy simulation (LES) approach. After a characterization of the wake flow topology, two applied methodologies are compared to each other with respect to the spatial and temporal resolution stressing their strengths and shortcomings. It is shown that both methods are well suitable for the prediction of the mean and instantaneous values of the turbulent velocity field, whereas for a reliable statistical analysis of the velocity fluctuations, the PIV approach is more appropriate due to the computational time limitations of the LES. On the other hand, the high spatial and temporal resolution of the LES allows for an accurate detection of relevant coherent structures as well as tracking their motion in time without any significant artificial vortex agglomeration that can be critical in the case of PIV. Furthermore, the influence of different model assumptions, e. g., the level of incoming turbulence and model vibrations, is discussed in order to emphasize the importance of a side-by-side combination of both investigation techniques.
© Owned by the authors, published by EDP Sciences, 2015