Effects of Effusion Cooling Pattern Near the Dilution Hole for a Double-Walled Combustor Liner—Part II: Flowfield Measurements

Shrager, Adam C.; Thole, Karen A.; Mongillo, Dominic

doi:10.1115/1.4041153

Cited by 12 publications

(4 citation statements)

References 16 publications

(37 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Shrager et al [23,24] perform thermal and aerodynamic analysis of a double-wall combustor liner. While the general impingement effusion setup is comparable, they focus on the area of dilution holes which are not included in this article's setup.…”

Section: Impingement Effusion Cooling Methods For Combustor Wallsmentioning

confidence: 99%

Experimental Study of Impingement Effusion-Cooled Double-Wall Combustor Liners: Thermal Analysis

2021

View full text Add to dashboard Cite

A new experimental study is presented for a combustor with a double-wall cooling design. The inner wall at the hot gas side features effusion cooling with 7-7-7 laidback fan-shaped holes, and the outer wall at the cold side features an impingement hole pattern with circular holes. Data have been acquired to assess the thermal and aerodynamic behavior of the setup using a new, scaled up, engine-similar test rig. Similarity includes Reynolds, Nusselt, and Biot numbers for hot gas and coolant flow. Different geometrical setups are studied by varying the cavity height between the two walls and the relative alignment of the two hole patterns at several different blowing ratios. This article focuses on the thermal performance of the setup. The temperature data are acquired using two infrared systems on either side of the effusion wall specimen. In addition to cooling effectiveness evaluations, finite element simulations are performed, yielding the locally resolved wall heat fluxes. Results are presented for three cavity heights and two longitudinal specimen alignments. The results show that the hot gas side total cooling effectiveness can achieve values as high as 90% and is mainly influenced by the effusion coverage. Impingement cooling has a small influence on overall effectiveness, and the area of influence is mainly located upstream where effusion cooling is not built up completely. The analyzed geometric variations show a major influence on cavity flow and impingement heat transfer. Small cavities lead to constrained flow and high local Nusselt numbers, while larger cavities show more equalized Nusselt number distributions. A present misalignment shows especially high influence at small cavity heights. The largest cavity height, in general, showed a decrease in heat transfer due to reduced jet momentum.

show abstract

Section: Impingement Effusion Cooling Methods For Combustor Wallsmentioning

confidence: 99%

Experimental Study of Impingement Effusion-Cooled Double-Wall Combustor Liners: Thermal Analysis

2021

View full text Add to dashboard Cite

show abstract

“…Shrager et al [15,16] performed thermal and aerodynamic analysis of a double-wall combustor liner. With a general impingement-effusion setup comparable to the one in this study, they focused on the area of dilution holes which are not included in this article's setup.…”

Section: Flow Analysis In Impingement Effusion Cooling Double-wallsmentioning

confidence: 99%

Experimental Study of Impingement Effusion Cooled Double-Wall Combustor Liners: Aerodynamic Analysis with Stereo-PIV

Jackowski¹,

Elfner²,

Bauer³

et al. 2021

Energies

View full text Add to dashboard Cite

A new experimental study is presented for a combustor with a double-wall cooling design. The inner wall at the hot gas side features effusion cooling with 7-7-7 laidback fan-shaped holes, and the outer wall at the cold side features an impingement hole pattern with circular holes. Data are acquired to asses the thermal and aerodynamic behavior of the setup, using a new, scaled up, engine similar test rig. Similarity includes Reynolds, Nusselt and Biot numbers for hot gas and coolant flow. Different geometrical setups are studied by varying the cavity height between the two walls and the relative alignment of the two hole patterns at two different impingement Reynolds numbers. This article focuses on the aerodynamic performance of the setup. Instationary flow data are acquired, using a high speed stereo PIV setup. For each geometrical configuration, approximately 20 planes are recorded with a data rate of 1000 by traversing the flow region of interest in the cavity between the two specimen. This fine resolution allows the reconstruction of 3D flow fields for the mean data values and an extensive analysis of transient phenomena at each plane. Time averaged data and jet-center plane transient data are presented in detail. The results show a complex flow field with a hexagonal vortex pattern in the cavity, which is mainly influenced by the cavity height and the relative alignment of the two walls. The jet Reynolds number shows small influence when analyzing normalized data. Small cavity heights show a less developed flow field with less stable vortex systems. The alignment shows a similar influence on vortex system stability, with the aligned case performing better. Additionally, statistical analysis of the jet flow and frequency domain analysis of the jet and the effusion flow are presented, showing the damping capability of the cavity, especially at increased cavity heights, and a residual low frequency pulsation of the effusion cooling inflow.

show abstract

“…In particular the Biot number, as discussed by Martiny et al [16], has a strong influence on overall distribution in effusion test cases. In laboratory condition, several researchers have conditioned the value of Biot number selecting a different material for the test plate or acting on the scale dimensions [17]. The recent interest of scientific research on heat transfer is moving toward additive manufacturing components at 1:1 scale in order to take into account effects of additive manufacturing [18].…”

Section: Dimensional Analysismentioning

confidence: 99%

A New Test Facility for Investigating Thermal Behaviour of Effusion Cooling Test Plates for RQL Combustors

Picchi

Andreini

Becchi

et al. 2020

Volume 7A: Heat Transfer

View full text Add to dashboard Cite

In aero engines the combustors are subjected to critical thermal conditions in terms of high temperatures and corrosive environment, which could affect the service life of the entire system. As well known, Thermal Barrier Coatings (TBC) and above all cooling systems represents the state-of-the-art in the nowadays protecting methods: the maximization of this beneficial effect is achieved by defining an optimal cooling arrangement and developing suitable manufacturing technologies for these systems. In modern aero-engine combustors, one of the most effective cooling scheme for liners is composed by an effusion perforation coupled with a slot system to start the film cooling. The cooling performances are deeply influenced by the mutual interactions between swirling and cooling flows. In addition, for typical Rich-Quench-Lean (RQL) combustor architectures, the injection of air provided to promoting the local break-down of the flame mixture fraction, deeply interacts with the swirled flow, generating recirculating structures capable of affecting the development of film cooling and making the design of cooling systems very challenging. A new test facility for testing effusion test plates for RQL combustors applications has been developed with the final aim of comparing different cooling strategies and at the same time to collect data for numerical model validation. The experimental set-up consists of a non-reactive planar sector rigs with 5 engine-scale swirlers fed with air up to 250 °C and 3 bar. The rig was equipped with outer/inner dilution ports, and a simple inner liner cooling scheme composed of effusion and a slot system: all these features, fed with air at ambient temperature, can be independently controlled in terms of mass flow. Using dedicated optical accesses, InfraRed (IR) camera tests were performed to retrieve overall effectiveness data imposing a temperature difference between swirling and cooling flows. To better understand those results, Pressure Sensitive Paint (PSP) technique was used to obtain reliable film effectiveness data decoupling the contribution of slot and effusion flows. The thermal characterization was supported by Particle Image Velocimetry (PIV) investigations on the median plane. Tests were performed at different pressure drops across swirler and varying the mass flows of slot and inner/outer liners. The analysis of the data highlighted the influences of the swirling flow on the overall thermal performance and the behaviour of the film cooling system.

show abstract

Effects of Effusion Cooling Pattern Near the Dilution Hole for a Double-Walled Combustor Liner—Part II: Flowfield Measurements

Cited by 12 publications

References 16 publications

Experimental Study of Impingement Effusion-Cooled Double-Wall Combustor Liners: Thermal Analysis

Experimental Study of Impingement Effusion-Cooled Double-Wall Combustor Liners: Thermal Analysis

Experimental Study of Impingement Effusion Cooled Double-Wall Combustor Liners: Aerodynamic Analysis with Stereo-PIV

A New Test Facility for Investigating Thermal Behaviour of Effusion Cooling Test Plates for RQL Combustors

Contact Info

Product

Resources

About