Numerical Investigation of Partial Blockage Effect on Film Cooling Effectiveness

Pan, Chengxiong; Zhang, Jingzhou; Ke-nan, Huang

doi:10.1155/2014/167193

Cited by 6 publications

(3 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Cheng et al [25] conducted a numerical investigation of the effects that deposition location and blowing ratio have on film cooling effectiveness using Fluent.…”

Section: 31: Deposit Effect On Film Coolingmentioning

confidence: 99%

The Effect of Particle Size on Deposition in an Effusion Cooling Geometry

Wolff

Bowen

Bons

2018

2018 AIAA Aerospace Sciences Meeting

View full text Add to dashboard Cite

The effect of particle size on particle accumulation within an effusion cooling geometry common to gas turbines was investigated experimentally and computationally.A flat plate with an effusion cooling hole array based on a gas turbine combustor liner was subjected to particulate laden flow in an accelerated deposition facility. The tests were conducted at an engine relevant plate temperature of 1118 K, coolant temperature of 950 K, and held at a constant pressure ratio of 1.03 (cavity to ambient). To elucidate the effect of particle size, six unique size distributions of Arizona Road Dust (ARD) smaller than 20 micron were introduced to the flow independently. Experiments were also conducted in which two different dust size distributions were sequentially delivered to the test article. These experiments clearly indicate that the smallest particles within the range tested accumulate within the hole creating deposit structures and blocking the effusion holes. They also indicate that larger particles within this range can have an erosive effect on the deposit structures as they build, changing the structure's morphology and blockage behavior.Computational fluid domains were developed to replicate the test article geometry before and after a test to investigate the effect that deposit structures have on deposition.Particles were introduced to these domains after reaching a steady solution and were tracked through the solution with a Lagrangian trajectory solver. The impact locations of iv the particles were recorded and a particle sticking model was employed to determine if the particles stick or rebound. The domain with the clean hole showed that the smallest particles impact and were prone to sticking in the area where deposits form experimentally. As the particles increase in size, the number of impacts and likelihood of sticking decreased. The domain with scoop deposit structures showed that these structures can change the particle impact trajectories influencing the buildup process.Overall, this body of work shows that particle size distribution has a first order effect on the blockage caused by particle deposition in effusion cooling geometries. The observation that 0.5-3 μm particles are primarily responsible for blockage while large particles can reduce deposit structure size highlights the complexity of particle deposition. This has significant implications for future work, particularly high fidelity modeling.v

show abstract

“…Cheng et al [25] conducted a numerical investigation of the effects that deposition location and blowing ratio have on film cooling effectiveness using Fluent.…”

Section: 31: Deposit Effect On Film Coolingmentioning

confidence: 99%

The Effect of Particle Size on Deposition in an Effusion Cooling Geometry

Wolff

Bowen

Bons

2018

2018 AIAA Aerospace Sciences Meeting

View full text Add to dashboard Cite

show abstract

“…Somawardhana et al [12] investigated the effect of geometric parameters on the cooling efficiency and found that the deposition shape had little effect on the cooling efficiency, but the deposition height had a great impact on the cooling efficiency. For the internal hole blockage, Pan et al [13] studied the effect of particle blockage in the monoclinic hole on film cooling, and analyzed the influence of different positions of the blockage in the hole on film cooling. The results showed that the blockage can severely affect the film cooling when it was on the upstream surface of the hole's inner wall.…”

Section: Introductionmentioning

confidence: 99%

Particle Deposition in the Vicinity of Multiple Film Cooling Holes

Peng

Luo

et al. 2022

Micromachines

View full text Add to dashboard Cite

Particle deposition on film cooling surface is an engineering issue that degrades the thermal protection of turbine blade. Here, we present a combined experimental and numerical investigation on the particle deposition in the vicinity of multiple film cooling holes to reveal the effect of interactions between cooling outflows on particle deposition. The numerical simulation of film cooling with a group of three rows of straight film cooling holes is conducted and validated by experimental data with blowing ratios ranging from 0 to 0.08. Wax particles with size range from 5 to 40 μm are added in the heated mainstream to simulate the particle deposition in the experiment. The simulation results show the decrease of particle deposition with blowing ratio and various deposition characteristics in different regions of the surface. The flow fields from numerical results are analyzed in detail to illustrate deposition mechanism of the particles in different regions under the interactions of cooling outflows. The cooling air from the holes in the first row reduces the particle concentration near the wall but causes particle deposition in or between the tail regions by the generated flow disturbance. The cooling air from the latter hole separates the diluted flow in the upstream from the wall, and creates a tail region without particle deposition. This revealed particle deposition characteristics under the effect of outflows interaction can benefit the understanding of particle deposition in engineering applications, where multi-row of cooling holes are utilized.

show abstract

“…The reasons causing the decrease or increase were analyzed through instantaneous flow field captured by Jovanovic et al [13]. Cheng et al [14] conducted a numerical investigation on hole-blockage. They found that the location of the blockage has much influence in the cooling effectiveness.…”

Section: Introductionmentioning

confidence: 99%

Combined Influence of Surface Deposition and Hole-Blockage on Film-Cooling Performances

Wang

Yuan

et al. 2016

Volume 5C: Heat Transfer

View full text Add to dashboard Cite

Commercial aero-engines may operate in dust-laden environments, such as taking off and landing on desert ground or flying through volcano dust cloud, and foreign particles frequently deposit at hot surface and film hole-exits, which results in partial blockage of film holes, clog of cooling air, reduction in cooling effect, and could induce catastrophic damage. This problem has not been well solved up to now. This paper presents an experimental investigation on two surface deposition models (deposition limited to upstream of hole with a peak height of 1.5 diameter of hole called D1.5, and downstream forming a trench with a peak height of 1.0 diameter of hole, called D1) and two blockage models (leading edge of hole LB, and trailing edge TB), as well as two combined models D1.5-LB, and D1-TB. The experiments are conducted in a low speed water tunnel using Planar Laser Induced Fluorescence (PLIF) technique. Through this experiment, the following interesting phenomena, which were not reported in previous literatures, are reveled: 1) The effect of blockage ratio at leading edge on cooling performance of combined D1.5-LB is opposite to individual LB, i.e. in the case of combined D1.5-LB, a higher blockage ratio corresponds to a lower cooling effectiveness; whereas, for individual LB, the cooling effectiveness increases with the blockage ratios in the tested range. 2) At all blowing ratios, the cooling performances of combined D1.5-LB are better than that of perfect model D0-B0 (without deposition and blockage). At all blockage ratios tested in this experiment, in the case of combined D1.5-LB, a higher blowing ratio corresponds to a higher cooling effectiveness and a lager film coverage length. 3) At lower blockage ratios of 0.1 and 0.3, the overall-averaged cooling effectiveness of combined D1-TB is higher than that of perfect model D0-B0. At large blockage ratio 0.5, the blockage effect is dominant, and the averaged cooling effectiveness of combined model D1-TB is lower than that of D0-B0. In the case of individual deposition model D1-B0, although the lateral-averaged film cooling effectiveness is augmented, the area of film cooling is reduced.

show abstract

Numerical Investigation of Partial Blockage Effect on Film Cooling Effectiveness

Cited by 6 publications

References 24 publications

The Effect of Particle Size on Deposition in an Effusion Cooling Geometry

The Effect of Particle Size on Deposition in an Effusion Cooling Geometry

Particle Deposition in the Vicinity of Multiple Film Cooling Holes

Combined Influence of Surface Deposition and Hole-Blockage on Film-Cooling Performances

Contact Info

Product

Resources

About