Analysis of the Onset of Dynamic Stall Using High-Fidelity Large-Eddy Simulations

Author(s):  
Miguel R. Visbal
AIAA Journal ◽  
2018 ◽  
Vol 56 (8) ◽  
pp. 2974-2991 ◽  
Author(s):  
Miguel R. Visbal ◽  
Stuart I. Benton

Author(s):  
Christoph Traxinger ◽  
Julian Zips ◽  
Christian Stemmer ◽  
Michael Pfitzner

Abstract The design and development of future rocket engines severely relies on accurate, efficient and robust numerical tools. Large-Eddy Simulation in combination with high-fidelity thermodynamics and combustion models is a promising candidate for the accurate prediction of the flow field and the investigation and understanding of the on-going processes during mixing and combustion. In the present work, a numerical framework is presented capable of predicting real-gas behavior and nonadiabatic combustion under conditions typically encountered in liquid rocket engines. Results of Large-Eddy Simulations are compared to experimental investigations. Overall, a good agreement is found making the introduced numerical tool suitable for the high-fidelity investigation of high-pressure mixing and combustion.


Author(s):  
Pawel J. Przytarski ◽  
Andrew P. S. Wheeler

Abstract In this paper we study the effect of rotor-stator axial gap on midspan compressor loss using high fidelity Large-Eddy Simulations. For this purpose we mimic the multi-stage environment using a new numerical method which recycles wake unsteadiness from a single blade passage back into the inlet of the computational domain. As a result a type of repeating-stage simulation is obtained such as observed by an embedded blade-row. We find that freestream turbulence levels rise significantly as the size of the rotor-stator axial gap is reduced. This is because of the effect of axial gap on turbulence production, which becomes amplified at smaller axial gaps and drives increases in dissipation and loss. This effect is found to raise loss by between 7–9.5% over the range of conditions tested here. This effect significantly outweighs the beneficial effects of wake recovery on loss.


Sign in / Sign up

Export Citation Format

Share Document