This paper presents a detailed experimental and computational investigation of the effects of scalloping on the mixing mechanisms of a scaled 12-lobe turbofan mixer. Scalloping was achieved by eliminating approximately 70% of the lobe sidewall area. Measurements were made downstream of the mixer in a co-annular wind tunnel, and the simulations were carried out using an unstructured Reynolds averaged Navier–Stokes (RANS) solver, Numeca FINE/Hexa, with SST model. In the core flow, the swirl angle was varied from to . At high swirl angles, a three-dimensional separation bubble was formed on the lobe's suction surface penetration region and resulted in the generation of a vortex at the lobe valley. The valley vortex quickly dissipated downstream. The mixer lobes removed most of the swirl, but scalloped lobes removed less swirl in the region of the scalloped notch. The residual swirl downstream of the scalloped mixer interacted with the vortices and improved mixing rates compared to the unscalloped mixer. Core flow swirl up to provided improved mixing rates and reduced pressure and thrust losses for both mixers. As core flow swirl increased beyond , the mixing rate continued to improve, but pressure and thrust losses declined compared to the zero swirl case. Lobe scalloping, in high swirl conditions, resulted in better mixing and improved pressure loss over the unscalloped mixer but at the expense of reduced thrust.
Effects of Scalloping on the Mixing Mechanisms of Forced Mixers With Highly Swirling Core Flow
Pratt & Whitney Canada,
Contributed by the International Gas Turbine Institute (IGTI) of ASME for publication in the Journal of Engineering for Gas Turbines and Power. Manuscript received October 8, 2012; final manuscript received November 26, 2012; published online June 10, 2013. Editor: David Wisler.
- Views Icon Views
- Share Icon Share
- Cite Icon Cite
- Search Site
Wright, A., Lei, Z., Mahallati, A., Cunningham, M., and Militzer, J. (June 10, 2013). "Effects of Scalloping on the Mixing Mechanisms of Forced Mixers With Highly Swirling Core Flow." ASME. J. Eng. Gas Turbines Power. July 2013; 135(7): 071202. https://doi.org/10.1115/1.4024043
Download citation file:
- Ris (Zotero)
- Reference Manager