An optimization study based on computational fluid dynamics (CFD) in combination with Stratford's analytical separation criterion was developed for the design of piecewise conical contraction zones and nozzles. The risk of flow separation was formally covered by a newly introduced dimensionless separation number. The use of this separation number can be interpreted as an adaption of Stratford's separation criterion to piecewise conical nozzles. In the nozzle design optimization process, the risk of flow separation was reduced by minimizing the separation number. It was found that the flow-optimized piecewise conical nozzle did not correspond to a direct geometric approximation of an ideal polynomial profile. In fact, it was beneficial to reduce the flow deflection in the outlet region for a piecewise conical nozzle to increase the nozzle performance. In order to validate the novel design method, extensive tests for different nozzle designs were conducted by means of wind tunnel tests. The measured velocity profiles and wall pressure distributions agreed well with the CFD predictions.
Optimization of Piecewise Conical Nozzles: Theory and Application
Muenster University of Applied Sciences,
Steinfurt 48565, Germany
Paderborn 33098, Germany
Contributed by the Fluids Engineering Division of ASME for publication in the JOURNAL OF FLUIDS ENGINEERING. Manuscript received October 29, 2018; final manuscript received May 2, 2019; published online June 7, 2019. Assoc. Editor: Philipp Epple.
- Views Icon Views
- Share Icon Share
- Search Site
Hasselmann, K., aus der Wiesche, S., and Kenig, E. Y. (June 7, 2019). "Optimization of Piecewise Conical Nozzles: Theory and Application." ASME. J. Fluids Eng. December 2019; 141(12): 121202. https://doi.org/10.1115/1.4043707
Download citation file: