Separation control in a conical diffuser with an annular inlet: center body wake separation
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In many practical applications of conical diffusers, the flow is fed by an annular flow passage formed by a center body. Flow separation, which occurs if the center body ends abruptly, is undesirable because it degrades the diffuser performance. The present experiment utilizes magnetic resonance velocimetry to acquire three-component mean velocity measurements for a set of conical diffusers with an annular inlet. The results show strong coupling between the diffuser wall boundary layer development and the wake of the center body. Coanda blowing is used to mitigate the center body wake separation. The diffuser wall boundary layer is thick in the absence of the central separation bubble and separates when Coanda blowing is too strong.
KeywordsCenter Body Separation Bubble Adverse Pressure Gradient Wake Vortex Conical Diffuser
Funding for this research is provided by Siemens Energy. Mr. Jongmin Seo assisted with the truncated Coanda tail piece experiments. Ms. Angelina Padilla assisted with all the MRV experiments that produced the data presented in this paper.
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