An influence of novel upstream steps on film cooling performance

Abdala, Antar M. M.; Elwekeel, Fifi N. M.

doi:10.1016/j.ijheatmasstransfer.2015.10.007

Cited by 28 publications

(6 citation statements)

References 22 publications

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“…But the shaped holes are expensive to manufacture. Instead of using holes with shaped exits, Elwekeel et al [8] and Abdala et al [9,10] shown that using the upstream step will improve the film cooling performance. But step studies need to optimize the steps dimensions and to decrease the aerodynamic losses.…”

Section: A Review Of Studies On Film Cooling Effectivenessmentioning

confidence: 99%

CFD Simulations of Film Cooling Effectiveness and Heat Transfer for Annular Film Hole

Abdala

Elwekeel

2016

Arab J Sci Eng

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The increasing turbine entry temperature has placed demands for improvements in engine cooling, and the work described in this paper is the development of a new film cooling configuration to meet this demand. In this study, numerical simulations were performed to predict the improvement in film cooling performance with novel film hole called an annular film hole. The film cooling performance parameters such as heat transfer coefficient (h), film cooling effectiveness (η) and the net heat flux reduction (NHFR) over flat plate were investigated and compared with other configurations. Velocity profiles, pressure coefficient and turbulence kinetic energy contours were discussed. Four mass flow rates of secondary flow fluid were used to investigate the effects of film coolant velocity on the film cooling performance behavior. Results indicate that an annular film hole gives high film effectiveness, low heat transfer coefficient and higher NHFR compared to rectangular and circular film holes. The average values of laterally averaged film cooling effectiveness of the annular film hole increased to 106 and 328.5 % compared with the rectangular and circular film holes at moderate flow rate, respectively. This difference is attributable to decreasing the jet vertical velocity component in a case of the annular hole. Also the low and high heat transfer coefficient regions were described for annular hole in detail. B Antar M. M. Abdala

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Section: A Review Of Studies On Film Cooling Effectivenessmentioning

confidence: 99%

CFD Simulations of Film Cooling Effectiveness and Heat Transfer for Annular Film Hole

Abdala

Elwekeel

2016

Arab J Sci Eng

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“…Bu amaçla son zamanlarda uygun ayrodinamik rampa tasarımının araştırıldığı çalışmalar yapılmıştır. Abdala ve Elwekeel [13] farklı kalınlıklardaki normal ve kavisli rampaları inelemişlerdir. Yaptıkları çalışmanın sonuçları, kalınlığı düşük ve kavisli rampaların film soğutmada daha iyi performans gösterdiğini göstermiştir.…”

Section: Gi̇ri̇ş (Introduction)unclassified

Numerical optimization of triangular concave edge shaped ramp in film cooling

TEPE

2022

Gazi Üniversitesi Mühendislik Mimarlık Fakültesi Dergisi

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 Film cooling effectiveness enhances with decreasing ramp angle  Film cooling effectiveness enhances with increasing ramp height  Ramp increases lateral spreading of the coolant stream Figure A. Detailed view of the physical model, a) section view, b) location of the ramp on the surface, c) numerical simulation region Purpose: Purpose of this study is to investigate the optimum design parameter of the triangular concave edge shaped upstream ramp under different flow condition for film cooling effectiveness. Theory and Methods: Numerical simulations were conducted using Ansys FLUENT. Performance of most widely used RANS model were compared and Transition k-kl-ω was used. Numerical solution procedure was validated with available experimental data in the literature. Area-averaged film cooling effectiveness (FCE), laterally-averaged FCE, longitudinally-averaged FCE and local FCE were quantitatively investigated comprehensively. In order to reveal the underlying physics of the influence of ramp on FCE, the vortices emerged in the flow field and the velocity profile of the flow were also examined. Results:Results showed that lateral spreading of the coolant were increased by locating ramp on the surface. Areaaveraged FCE is enhanced 305.44% with h/d=0.50 and αr=10˚ compared to conventional film cooling configuration. While highest area-averaged FCE achieved at relatively low blowing ratio (M=0.60) for conventional film cooling, increasing blowing ratio also increases area-averaged FCE by mounting upstream ramp on the surface. Conclusion:Counter rotating vortex (CRV) on the coolant flow detaches the coolant from the surface. Ramp creates anti-CRV on the coolant flow and prevents the coolant separation. Strength of anti-CRV on jet flow increases with decreasing ramp angle and increasing ramp height, therefore FCE increases with decreasing ramp angle and increasing ramp height. Furthermore, most feasible design parameters of ramp for film cooling effectiveness are h/d=0.50 and αr=10˚

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“…al [33] conducted a similar experiment with various hole geometries using the PSP technique. Abdala and his colleagues [34,35] presented the numerical investigations with various upstream ramp geometries. Velocity profiles and pressure coefficient profiles were discussed in their paper.…”

Section: Introductionmentioning

confidence: 99%