Film Cooling From Short Holes With Sister Hole Influence

Ely, Marc J.; Jubran, B. A.

doi:10.1115/gt2012-68081

Cited by 16 publications

(21 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Figure 17 below shows the result for centre-line adiabatic effectiveness for blowing ratio, M=1.0 for the current study and compared to the result of Ely and Jubran [32]. From the graph, we can observe a big difference of overall center-line adiabatic film effectiveness.…”

Section: Comparison With Past Researchmentioning

confidence: 78%

“…The results of the current study is compared with past research of Ely and Jubran [32] which utilises the addition of sister holes at 35°. From the comparison, the application of 30° sister hole has better film cooling effectiveness especially with the increase of spanwise distance at low blowing.…”

Section: Discussionmentioning

confidence: 98%

“…The results of current study will be compared with the result obtained through the study of Ely and Jubran [32]. Figure 17 below shows the result for centre-line adiabatic effectiveness for blowing ratio, M=1.0 for the current study and compared to the result of Ely and Jubran [32].…”

Section: Comparison With Past Researchmentioning

confidence: 93%

See 2 more Smart Citations

An Experiment Investigation of Film Cooling Effectivenes of Sister Hole of Cylindrical Shaped Hole Film Cooling Geometry on a Flat Plate Surface

Yazid

Salleh

2015

AMM

View full text Add to dashboard Cite

Gas turbines are widely used nowadays for aircraft propulsion and in land-based power generation or in the industrial application. The operating temperature of gas turbine has to be increased in order to increase their effectiveness. Thus, a cooling method known as film cooling is introduced to cool down the high operating temperature of the gas turbine. Film cooling is one of the effective methods in reducing the heat load to a turbine airfoil. This method is cost effective and by far the most common and widely researched method in the industry. Film cooling effectiveness plays a vital role in modern gas turbine technology. This present study will focus on sister holes that are attached to the primary holes at shallow angle of 30°, with 4 different blowing ratios ranging from 0.5 to 2.0. The roles of the different in blowing ratios are to observe the different values of film effectiveness presented by the sister holes design and to select the most effective blowing ratio that suits the design at shallow angle. From the results obtained, the usage of sister holes with shallow angle further increases the film cooling effectiveness particularly at low blowing ratio.

show abstract

Section: Comparison With Past Researchmentioning

confidence: 78%

Section: Discussionmentioning

confidence: 98%

See 1 more Smart Citation

An Experiment Investigation of Film Cooling Effectivenes of Sister Hole of Cylindrical Shaped Hole Film Cooling Geometry on a Flat Plate Surface

Yazid

Salleh

2015

AMM

View full text Add to dashboard Cite

show abstract

“…Ely and Jubran [61]- [65] conducted series of studies in sister holes film cooling, which were the first to document the sister hole film cooling using multiple round holes, as shown in Figure 2.7. They found a significant improvement in both centerline and lateral cooling effectiveness, not only at low blowing ratios but also at high blowing ratios in comparison to a single round hole [61]- [65]. and Jubran [66] in which five sister hole locations were tested in both directions at M= 0.2-1.5.…”

Section: Sister Holes Film Coolingmentioning

confidence: 99%

Numerical Analysis of Film Cooling Performance of Micro Holes and Compound Angle Sister Holes

Alsalam¹

2021

Preprint

View full text Add to dashboard Cite

In the present research, micro holes and compound angle sister holes have been numerically investigated as two different techniques to enhance the cylindrical hole cooling performance, which suffers from a low cooling performance at high blowing ratio. The numerical analysis is performed over a flat plate model to assess the film effectiveness and the associated flow field at low and high blowing ratios. The performance assessment of the discrete round micro hole with a 200 µm diameter reveals that the micro hole yields the best cooling performance at low blowing ratios, and there is nearly 30% increase in the overall film cooling effectiveness compared to that of the round macro hole. The flow field results demonstrate the presence of a Counter-Rotating Vortex Pair (CRVP) at a smaller size and less strength, thus, contributed to better spanwise spreading of the coolant jet and lateral film cooling effectiveness. Micro holes present an improvement in the lateral film cooling effectiveness at high freestream turbulence intensity and high blowing ratios. Computational evaluation of the CFD prediction capability of the sister holes cooling effectiveness using five RANS turbulence models has been carried out as well as an assessment of the effects of the near-wall modeling on the predicted lateral effectiveness. The turbulence models used are realizable k-epsilon, standard k-epsilon, RNG k-epsilon, Reynolds stress model, and Spalart-Allmaras model. It is generally found that realizable k-ε combined with the enhanced wall treatment provides the best prediction of the numerical results in comparison to the experimental measurements at a low blowing ratio while an underprediction of the lateral performance is found at a high blowing ratio from all examined turbulence models. The compound angle upstream sister holes (CAUSH) have been proposed as a novel and simple design of the cooling hole whereas the numerical results have shown a notable increase in both centerline and lateral effectiveness for all tested compound angles at all blowing ratios. The anti-counter rotating vortices pair (ACRVP) structure generated from the compound angle upstream sister holes has actively controlled the flow field and maintained the coolant jet fully attached to the plate surface while restraining the coolant lift-off at high blowing ratios. Finally, the influence of the compound angle sister holes streamwise location on the thermal and flow field performance has also been analyzed, whereas three locations: upstream, midstream, and downstream are examined. It is found that the midstream and downstream locations offered a considerable increase in the cooling effectiveness, which is very much dependent on the blowing ratio and the area downstream of the cooling holes. In addition, the optimum centerline effectiveness is obtained by the downstream location, while the best lateral effectiveness is attained through the midstream location.

show abstract

“…The array consists of 5 sets of sister holes with a pitch of 4.5D. The data is collected from all 5 sets of holes and is compared with Ely et al[4]. The drawing of the film hole is shown inFigure 2.Data Analysis.…”

mentioning

confidence: 99%

Experimental Study on Film Cooling Effectiveness of Shallow Hole with Upstream Sister Holes

Salleh

Yee

2015

AMM

View full text Add to dashboard Cite

In order to increase the thermal efficiency of a gas turbine, the operating temperature has to be increased. This increment may cause the material of the blade to melt. Film cooling is a good option to solve this problem. Various studies has been done on film cooling include the shallow hole and sister holes. The present study focused on an experimental of film cooling effectiveness on shallow hole of 20° with upstream sister holes with 3 blowing ratios which are 1.0, 15 and 2.0. The result showed significant improvement compared to shallow hole of 35°. The optimum blowing ratio is 1.5. Smaller shallow angle and upstream sister holes reduce the jet lifting effect of the secondary air flow. Future study can be done on shallow hole of shallow angle and blowing ratio around 1.5 in order to further improve the film cooling effectiveness.

show abstract

Film Cooling From Short Holes With Sister Hole Influence

Cited by 16 publications

References 0 publications

An Experiment Investigation of Film Cooling Effectivenes of Sister Hole of Cylindrical Shaped Hole Film Cooling Geometry on a Flat Plate Surface

An Experiment Investigation of Film Cooling Effectivenes of Sister Hole of Cylindrical Shaped Hole Film Cooling Geometry on a Flat Plate Surface

Numerical Analysis of Film Cooling Performance of Micro Holes and Compound Angle Sister Holes

Experimental Study on Film Cooling Effectiveness of Shallow Hole with Upstream Sister Holes

Contact Info

Product

Resources

About