Numerical study and GMDH-type neural networks modeling of plasma actuator effects on the film cooling over a flat plate

Dolati, Samera; Amanifard, Nima; Deylami, Hamed Mohaddes

doi:10.1016/j.applthermaleng.2017.05.149

Cited by 18 publications

(4 citation statements)

References 27 publications

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“…They concluded that at different values of blowing ratios, an injection angle of 30 degree achieves the highest FCE. The same conclusion has also been found at low blowing ratios and at different ratio of transverse pitch to injection angle [23]. Numerical studies on film cooling technique are mostly focused on selecting the best turbulence model to effectively estimate film-cooling performance.…”

Section: Introductionsupporting

confidence: 60%

“…It has been reported that inclined jet (hole) angle influences the effectiveness of cooling uniformity [22]. The effect of different hole shape has been explored in literature [23] and it is reported that fan-shaped hole shows improved film cooling effectiveness when compared to a cylindrical hole. To sum up, the main outcome from the previous studies [15][16][17][18][19][20][21][22] is that for a specific turbulent intensity value at a specific angle, increasing the blowing ratio increases the film cooling effectiveness (FCE) up to a critical blowing ratio.…”

Section: Introductionmentioning

confidence: 99%

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Optimization of a Confined Jet Geometry to Improve Film Cooling Performance Using Response Surface Methodology (RSM)

2020

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This study investigates the interrelated parameters affecting heat transfer from a hot gas flowing on a flat plate while cool air is injected adjacent to the flat plate. The cool air forms an air blanket that shield the flat plate from the hot gas flow. The cool air is blown from a confined jet and is simulated using a two-dimensional numerical model under three variable parameters; namely, blowing ratio, jet angle and density ratio. The interrelations between these parameters are evaluated to properly understand their effects on heat transfer. The analyses are conducted using ANSYS-Fluent, and the performance of the air blanket is reported using local and average adiabatic film cooling effectiveness (AFCE). The interrelation between these parameters and the AFCE is established through a statistical method known as response surface methodology (RSM). The RSM model shows that the AFCE has a second order relation with the blowing ratio and a first order relation with both jet angle and density ratio. Also, it is found that the highest average AFCE is reached at an injection angle of 30 degree, a density ratio of 1.2 and a blowing ratio of 1.8.

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Section: Introductionsupporting

confidence: 60%

Section: Introductionmentioning

confidence: 99%

Optimization of a Confined Jet Geometry to Improve Film Cooling Performance Using Response Surface Methodology (RSM)

2020

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“…Later, He et al [23][24][25] further investigated the effects of the position, power input, number, and geometry of the DBDPA on the FCP, providing a deeper understanding of the mechanism of the PAA for improving the film cooling efficiency. Recently, Dolati et al [26] employed neural networks to generalize the complicated communication that involves variables (e.g., flow, geometric, and electrical variables), thus gaining a useful correlation with different input-output parameters. Accordingly, Audier et al [27] explored the ability of the PAA for the film cooling efficiency's enhancement through an experimental setup, and the experimental results confirmed the advantages of the PAA for improving the film cooling efficiency as predicted by the abovementioned numerical findings.…”

Section: Introductionmentioning

confidence: 99%

Large Eddy Simulation of Pulsed Film Cooling with a Dielectric Barrier Discharge Plasma Actuator

Shen,

Hu,

et al. 2023

Aerospace

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The effects of the coolant pulsation and the plasma aerodynamic actuation (PAA) on the film cooling are herein explored via large eddy simulations. The electrohydrodynamic force derived from the PAA was solved through the phenomenological plasma model. The Strouhal number of the sinusoidal coolant pulsation and the averaged pulsation blowing ratio were 0.25 and 1.0, respectively. Comprehensive analyses were carried out on the time-averaged flow fields, and the results reveal that the pulsed cooling jet might cause a deeper penetration into the crossflow, and this phenomenon could be remarkably mitigated by the downward force of the PAA. Comparing steady film cooling to pulsed film cooling revealed a modest 15.1% reduction in efficiency, while the application of the dielectric barrier discharge plasma actuator (DBDPA) substantially enhanced the pulsed film cooling efficiency by 42.1%. Moreover, the counter-rotating vortex pair (CRVP) was enlarged and lifted off from the wall more poorly due to the coolant pulsation, and the PAA weakened the detrimental lift-off effect and entrainment of the CRVP. Then, the spatial–temporal development of the coherent structures was figured out by the alterations in the centerline temperature, reflecting the formation of the intermittent coherent structures rather than hairpin vortices due to the coolant pulsation, and their size and upcast behaviors were reduced by the PAA; thus, the turbulent integration of the coolant with the crossflow was suppressed fundamentally. Finally, the three-dimensional streamlines confirmed that the coherent structure dynamic behaviors were significantly regulated by the PAA for alleviating the adverse influences of the coolant pulsation. In summary, the PAA can effectively improve the pulsed film cooling efficiency by controlling the spatial–temporal development of the dominant coherent structures.

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“…They utilized a convolutional neural network to forecast relations between coolant jet film and mainstream hot jet. Dolati et al (20) studied the film cooling effectiveness by building a GMDH-type neural network to model the plasma actuator effects over a flat plate. Yang et al (21) employed convolution modeling to predict the plugging problems and cooling efficiency of transpiration film cooling in the study.…”

Section: Introductionmentioning

confidence: 99%

Deep‐Learning-Based Uncertainty Analysis of Flat Plate Film Cooling With Application to Gas Turbine

Wang

Qiu

Qian

et al. 2023

Aerosp. Res. Commun.

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Nowadays, gas turbines intake jet air at high temperatures to improve the power output as much as possible. However, the excessive temperature typically puts the blade in the face of unpredictable damage. Film cooling is one of the prevailing methods applied in engineering scenarios, with the advantages of a simple structure and high cooling efficiency. This study aims to assess the uncertain effect that the three major film cooling parameters exert on the global and fixed-cord-averaged film cooling effectiveness under low, medium, and high blowing ratios br. The three input parameters include coolant hole diameter d, coolant tube inclination angle θ, and density ratio dr. The training dataset is obtained by Computational Fluid Dynamics (CFD). Moreover, a seven-layer artificial neural network (ANN) algorithm is applied to explore the complex non-linear mapping between the input flat film cooling parameters and the output fixed-cord-averaged film cooling effectiveness on the external turbine blade surface. The sensitivity experiment conducted using Monte Carlo (MC) simulation shows that the d and θ are the two most sensitive parameters in the low-blowing-ratio cases. The θ comes to be the only leading factor of sensitivity in larger blowing ratio cases. As the blowing ratio rises, the uncertainty of the three parameters d, θ, and dr all decrease. The combined effect of the three parameters is also dissected and shows that it has a more significant influence on the general cooling effectiveness than any single effect. The d has the widest variation of uncertainty interval at three blowing ratios, while the θ has the largest uncertain influence on the general cooling effectiveness. With the aforementioned results, the cooling effectiveness of the gas turbine can be furthermore enhanced.

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Numerical study and GMDH-type neural networks modeling of plasma actuator effects on the film cooling over a flat plate

Cited by 18 publications

References 27 publications

Optimization of a Confined Jet Geometry to Improve Film Cooling Performance Using Response Surface Methodology (RSM)

Optimization of a Confined Jet Geometry to Improve Film Cooling Performance Using Response Surface Methodology (RSM)

Large Eddy Simulation of Pulsed Film Cooling with a Dielectric Barrier Discharge Plasma Actuator

Deep‐Learning-Based Uncertainty Analysis of Flat Plate Film Cooling With Application to Gas Turbine

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