Turbine Vane Leading Edge Impingement Cooling With a Sweeping Jet

Abstract

A low speed linear cascade was used to investigate sweeping jet impingement cooling in a nozzle guide vane leading edge at an engine-relevant Biot number. Sweeping and steady jets were studied at varying mass flow rates and freestream turbulence intensities. Infrared thermography and a thermal inertia technique were used to determine the overall cooling effectiveness and internal heat transfer coefficients of the impingement cooling configurations. The circular jet array provided higher overall effectiveness values at both freestream turbulence intensities. The sweeping jet array provided a broader heat transfer profile due to the spreading of the jet. Pressure drop was measured for each jet geometry, and the circular jet was found to have less pressure drop than the sweeping jet at a given mass flow rate.

Design of a novel vortex-based feedback fluidic oscillator with numerical evaluation

“…The oscillations of flow in the fluidic oscillators are used in many applications such as heat transfer enhancement of gas turbine blades (Agricola et al, 2018;Hossain et al, 2017;Kim et al, 2017), controlling the flow separation (Andino et al, 2015;Koklu, 2018;Tesař et al, 2013),measuring the mass flow rate (Madadkon et al, 2012) and harvesting energy (Alikhassi et al, 2019).…”

Numerical Simulation on Internal Flow and Heat Transfer of Sweeping Jet and Film Composite Cooling on a Flat Plate

“…Kim (2019) found that the overall cooling effectiveness of fluidic oscillator was higher than normal jet when normalized injection distance was less than 5. Significantly, Agricola (2018) investigated the aerodynamic and heat transfer characteristics of fluidic oscillator and normal jet with different mass flow rates and turbulence on a low-speed cascade test rig. Experimental results showed that the cooling effectiveness of normal jet exceeded sweeping jet, and the aerodynamic loss was smaller when the normalized injection distance was 5, but sweeping jet covered a wider area.…”

“…Experimental results showed that the cooling effectiveness of normal jet exceeded sweeping jet, and the aerodynamic loss was smaller when the normalized injection distance was 5, but sweeping jet covered a wider area. The reason for the divergence might be that the impinging surface was concave in the experiment of Agricola (2018), large-scale vortices were formed on both sides of jet core region, and the cooling effectiveness was reduced because the coolant with higher temperature was sucked into core region. Therefore, similar to the impingement and film composite structures mentioned above, current work is to set film holes on both sides of core region to extract large-scale vortices from the impingement cavity and spread a layer of film on the outer surface to isolate the direct erosion of gas.…”