Large-eddy simulation of sonic coaxial jets with different total pressure ratios of the inner to outer nozzle

2018 ◽  
Vol 171 ◽  
pp. 122-134 ◽  
Author(s):  
Hai-Tao Shi ◽  
Nan-Sheng Liu ◽  
Pei Wang ◽  
Xi-Yun Lu
Keyword(s):  
Large Eddy Simulation ◽  
Total Pressure ◽  
Coaxial Jets ◽  
Eddy Simulation ◽  
Large Eddy

Loss Predictions in the High-Pressure Film-Cooled Turbine Vane of the FACTOR Project by Mean of Wall-Modeled Large Eddy Simulation

2020 ◽  
Author(s):  
Mael Harnieh ◽  
Nicolas Odier ◽  
Jérôme Dombard ◽  
Florent Duchaine ◽  
Laurent Gicquel
Keyword(s):  
Spatial Distribution ◽  
Large Eddy Simulation ◽  
Film Cooling ◽  
Total Pressure ◽  
Mean Flow ◽  
Cooling Effectiveness ◽  
Film Cooling Effectiveness ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Turbine Vane

Abstract The use of numerical simulations to design and optimize turbine vane cooling requires precise prediction of the fluid mechanics and film cooling effectiveness. This results in the need to numerically identify and assess the various origins of the losses taking place in such systems and if possible in engine representative conditions. Large-Eddy Simulation (LES) has shown recently its ability to predict turbomachinery flows in well mastered academic cases such as compressor or turbine cascades. When it comes to industrial representative configurations, the geometrical complexities, high Reynolds and Mach numbers as well as boundary condition setup lead to an important increase of CPU cost of the simulations. To evaluate the capacity of LES to predict film cooling effectiveness as well as to investigate the loss generation mechanisms in a turbine vane in engine representative conditions, a wall-modeled LES of the FACTOR film-cooled nozzle is performed. After the comparison of integrated values to validate the operating point of the vanes, the mean flow structure is investigated. In the coolant film, a strong turbulent mixing process between coolant and hot flows is observed. As a result, the spatial distribution of time-averaged vane surface temperature is highly heterogeneous. Comparisons with the experiment show that the LES prediction fairly reproduces the spatial distribution of the adiabatic film effectiveness. The loss generation in the configuration is then investigated. To do so, two methodologies, i.e, performing balance of total pressure in the vanes wakes as mainly used in the literature and Second Law Analysis (SLA) are evaluated. Balance of total pressure without the contribution of thermal effects only highlights the losses generated by the wakes and secondary flows. To overcome this limitation, SLA is adopted by investigating loss maps. Thanks to this approach, mixing losses are shown to dominate in the coolant film while aerodynamic losses dominate in the coolant pipe region.

Large-Eddy Simulation of Coaxial Jets: Coherent Structures and Mixing Properties

2006 ◽  
pp. 277-284 ◽  
Author(s):  
Guillaume Balarac ◽  
Mohamed Si-Ameur ◽  
Olivier Métais ◽  
Marcel Lesieur
Keyword(s):  
Large Eddy Simulation ◽  
Coherent Structures ◽  
Mixing Properties ◽  
Coaxial Jets ◽  
Eddy Simulation ◽  
Large Eddy
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