Improved film cooling from cylindrical angled holes with triangular tabs: effect of tab orientations

Nasir, Hasan Arshad; Acharya, Sumanta; Ekkad, Srinath V.

doi:10.1016/s0142-727x(03)00082-1

Cited by 62 publications

(23 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Recent turbine blades employ the internal convection cooling enhanced by turbulence promoting ribs in the blades and the external film cooling achieved by air jets along the blade outer surface, with aiming at both surface temperature reduction and heat flux reduction. Although many studies on the cooling performance have been reported so far (e.g., Eriksen et al (1) , Schmidt et al (2) , Ekkad et al (3) , Nasir et al (4) ), studies on the interaction between internal convection cooling and external film cooling are quite limited. Thole et al (5) investigated the effect of the flow velocity in the internal passage whose direction is parallel to the external main flow direction.…”

Section: Introductionmentioning

confidence: 99%

Effect of Orientation of Internal Turbulence Promoting Ribs on Flow Characteristics for Film Cooling

Agata

Takahashi

Shimizu

et al. 2013

JTST

View full text Add to dashboard Cite

Numerical simulations have been performed to study the film cooling of a flat plate that has an internal cooling passage perpendicular to the main flow. The goal is to understand the effect of the orientation of turbulence promoting ribs installed in the internal cooling passage on the adiabatic film cooling effectiveness in the external main flow downstream of the cooling-air injection. Detached Eddy Simulation is carried out for the flow characteristics for two rib orientations at two blowing ratios. The simulation results have revealed that the rib orientation affects significantly the temperature and flow structures downstream of the cooling hole and therefore affects the film-cooling performance on the surface. The revealed difference is due to the presence/absence of intense spiral motion at the cooling-hole outlet and such a difference originates from an interaction between the flow separation behind the inclined rib and the flow suction at the inlet of inclined cooling hole. The simulation results are exploited to draw a clear picture for the fluid-dynamical mechanisms responsible for the effect of the rib orientation.

show abstract

Section: Introductionmentioning

confidence: 99%

Effect of Orientation of Internal Turbulence Promoting Ribs on Flow Characteristics for Film Cooling

Agata

Takahashi

Shimizu

et al. 2013

JTST

View full text Add to dashboard Cite

show abstract

“…Nasir et al [12] investigated triangular tabs that are located along upstream edge of the holes. These tabs increased cooling effectiveness, but this application showed increase in pressure drop.…”

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

View full text Add to dashboard Cite

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

show abstract

“…Na et al [8] proposed a ramp upstream of the holes to modify the approaching boundary-layer flow and its interaction with the film-cooling jets. Nasir et al [9] investigated the effect of discrete delta-shaped tabs with different orientations on the film cooling performance from a row of cylindrical holes. Ghorab et al [10,11] investigated the hybrid and the louver schemes using Thermochromic Liquid Crystal technique.…”

Section: Introductionmentioning

confidence: 99%

Effects of chemical reaction caused by cooling stream on film cooling effectiveness

et al. 2012

View full text Add to dashboard Cite

With the increase of inlet temperature of gas turbines, the benefits by using the conventional methods are likely to approach their limits. Therefore, it is essential to study novel film cooling methods for surpassing these current limits. Based on the theory of heat transfer enhancement, a film cooling method with chemical reaction by cooling stream is proposed. In order to test the feasibility of the proposed method, numerical simulations have been conducted. The classic flat plate structure with a 30 degree hole is used for the simulation. In the present study, the effects of the parameters in relation to the chemical reaction on film cooling effectiveness, such as chemical heat sink, volume changes, and reaction rate, are investigated numerically. The conventional film cooling is also calculated for the comparison. The results show that film cooling effectiveness is improved obviously due to the chemical reaction, and the reaction heat and reaction rate of cooling stream have an important effect on film effectiveness. However, the effect of volume changes can be ignored.

show abstract

Improved film cooling from cylindrical angled holes with triangular tabs: effect of tab orientations

Cited by 62 publications

References 19 publications

Effect of Orientation of Internal Turbulence Promoting Ribs on Flow Characteristics for Film Cooling

Effect of Orientation of Internal Turbulence Promoting Ribs on Flow Characteristics for Film Cooling

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

Effects of chemical reaction caused by cooling stream on film cooling effectiveness

Contact Info

Product

Resources

About