Passive mixing devices such as chevrons and tabs are being explored by aircraft engine manufacturers as well as NASA to enhance mixing between fan and core streams and reduce noise from the exhaust. CRAFT Tech has played a leading role in supporting the analyses of these configurations. The RANS solutions predicted by the CRAFT CFD code are used as inputs to the MGBK noise code for assessing jet noise reduction resulting from the enhancement in the mixing. CRAFT Tech simulations have demonstrated the critical role of turbulence models in yielding accurate noise predictions. In particular, advanced non-isotropic, algebraic Reynolds stress (EASM) models have been validated for this flow regime as part of this effort. Recent work has entailed use of LES methodology and examination of non-passive devices involving micro-jets and polymer injection.

Kannepalli, C., Kenzakoski, D.C.,a nd Dash, S.M., “Analysis of Supersonic Jet Noise Reduction Concepts,” AIAA Paper No. AIAA-2003-1201, 41st AIAA Aerospace Meeting, Reno, NV, January, 2003.

Kenzakowski, D.C., Papp, J.L., and Dash, S.M., “Modeling Turbulence Anisotropy For Jet Noise Prediction,” AIAA 2002-0076, 40th AIAA Aerospace Sciences Meeting, Reno, NV, January, 2002.

Kenzakowski, D.C., and Dash, S.M., " Study Of Three-Stream Laboratory Jets With Passive Mixing Enhancements For Noise Reduction," AIAA Paper No. 2000-0219, 38th AIAA Aerospace Sciences Meeting at Reno, NV, Jan 10-13, 2000.

Dash, S.M., Kenzakowski, D.C., Perrell, E.R., Cavallo, P.A., Chidambaram, N., and Sinha, N., "Advances in Simulation of Passive Jet Noise Reduction," AIAA-98-2268 4th AIAA/CEAS Joint Aeroacoustics Conference, Toulouse, France, June 2–4, 1998.