On the suitability of direct application of acoustic theory to time-resolved tomographic PIV tested by DNS for low Mach number jet flows

On the suitability of direct application of acoustic theory to time-resolved tomographic PIV tested by DNS for low Mach number jet flows

Moore, P.
Violato, D.
Bryon, K.
Scarano, F.

Aerospace Engineering

Aerodynamics, Wind Energy & Propulsion

2010-06-07

In this paper, we investigate the minimum temporal requirements, spatial domain and spatial resolution requirements in order to make acoustic predictions by means of acoustic analogies, for low speed jet flows, by means of numerical simulations. This work is done to demonstrate the feasibility of indirect acoustic extrapolation from recent experiments undertaken by us and to develop robust techniques. For this paper we consider Direct Numerical Simulation of incompressible jets flows of Reynolds number 2,500 and Reynolds number 5,000 jets. Comparison of flow statistics and visualizations confirms that the simulations are representative of the jets obtained in our experiments. Lighthill’s and Powell’s aerocaoustic analogies are applied and demonstrated to yield indirect acoustic predictions of these jets, especially at 90º to the flow axis, where the coordinate origin dependency of Powell’s acoustic analogy is minimal. Finally we investigate the robustness of these indirect acoustic predictions when the DNS simulation data is reduced in temporal and spatial extent and resolution to those currently achievable by our Tomographic PIV setup. The results indicate that our current measurement capabilities are suitable for obtaining acoustic spectra up to a Strouhal number of 1.0. Moreover, in order to improve the spectral cut-off, it is preferable to increase the spatial resolution of the measurements at the expense of domain size and temporal resolution.

http://resolver.tudelft.nl/uuid:72716931-3cb0-47c4-a320-f867d772d935

https://doi.org/10.2514/6.2010-3960

American Institute of Aeronautics and Astronautics (AIAA)

978-1-60086-955-6

16th AIAA/CEAS Aeroacoustics Conference, Stockholm, Sweden, 7-9 June 2010; AIAA 2010-3960

Institutional Repository

conference paper

© 2010 American Institute of Aeronautics and Astronautics