Computational and Experimental Evaluation of a Complex Inlet Swirl Pattern Generation System

Sanders, Darius; Nessler, Chase; Copenhaver, William W.; List, Michael G.; Janczewski, Timothy

doi:10.2514/6.2016-5008

Cited by 12 publications

(5 citation statements)

References 10 publications

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“…The similarities of the small-scale flow with the full-scale experiment indicate that there are no further physics that need to be described for the higher Reynolds number flow that is far enough upstream of the engine fan face and outside of the duct inner-diameter boundary layer. This has also been previously observed by Sanders et al [30] for a more complex StreamVane pattern, and compared to computational fluid dynamics results.…”

Section: Resultssupporting

confidence: 83%

“…The full-scale StreamVane seem to overshoot the higher angles, relative to the small-scale flow angles, but since the near-wall data was filtered for the small-scale experiment, this cannot be verified. The overall shape of the distortion distribution is maintained across scales, as shown previously for more complex geometries by Guimarães et al [29] and Sanders et al [30]. Most of the other regions of the radius seem to agree well across scales, mainly when taking into account the uncertainty of the measurements (plots for the same values with error bars are presented in the Appendix).…”

Section: Resultssupporting

confidence: 77%

“…PIV experimental setup (left), and details of the laser sheet intersecting with the acrylic pipe (right[30]). …”

mentioning

confidence: 99%

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Vortical flow development in round ducts across scales for engine inlet applications

2019

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Turbofan engine performance depends highly on the characteristics and conditions of the inlet flow. Swirl distortions, caused by non-uniformities in flows arising from boundary layer or ground/fuselage vortex ingestion are of concern and need to be fully understood to guarantee efficiency and safety of propulsion systems. To investigate a fundamental single-vortex distortion development in a duct at different Reynolds numbers, a StreamVane distortion generating device was designed and experimentally analyzed in a small-scale low-speed wind tunnel (Re D 500 × 10 3 ) and in a full-scale engine testing rig (Re D 3 × 10 6 ). Stereoscopic particle image velocimetry was used to measure the three-component velocity fields at discrete measurement planes downstream of the distortion device. Results show that the secondary flow is generated and develops very similarly in both scales, and is mostly driven by two-dimensional (2D) vortex dynamics. Induced velocities arising from the proximity of the vortex to the duct wall causes the vortex center to convect circumferentially around the duct, in the same sense as the vortex rotation, as it travels downstream. Small-scale turbulence results show small-scale instabilities related to the development of the vortex. This work shows that the development of this vane-generated, vortex-dominated flow is largely Reynolds number independent for the covered range, so that details of similar duct-bounded flows can be analyzed in depth in small-scale experiments, decreasing development efforts and cost. arXiv:1808.07273v1 [physics.flu-dyn]

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Section: Resultssupporting

confidence: 83%

Section: Resultssupporting

confidence: 77%

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Vortical flow development in round ducts across scales for engine inlet applications

2019

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“…The StreamVane has been shown versatile and effective in generating complex distortion profiles, as the HWB profile presented in this work, single vortex distortions [25], and twin vortex distortions [19,26,27]. It is important, however, to acknowledge that it is a device added to the inlet of the engine, and its influence to the flow needs to be analyzed to ensure that possible adverse effects to the flow are minimized.…”

Section: Resultsmentioning

confidence: 99%

“…Here, the StreamVane TM technology [13,17] is used to generate a distortion profile inspired by the base distortion features of an extreme flight condition for an experimental design of a HWB engine inlet. Prior findings on StreamVane aerodynamics indicate that the dominant secondary flow dynamics are Reynolds number independent [17,18], and that the generation of the distortions is Mach number independent until vanes choke [19]. For low-speed small scale wind tunnel experiments of single vortex distortions, secondary flow development is well-predicted by inviscid dynamics of axial vorticity [20].…”

Section: Introductionmentioning

confidence: 90%

Complex Flow Generation and Development in a Full-Scale Turbofan Inlet

Guimarães

Lowe

O’Brien

2018

Journal of Engineering for Gas Turbines and Power

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The future of aviation relies on the integration of airframe and propulsion systems to improve aerodynamic performance and efficiency of aircraft, bringing design challenges, such as the ingestion of nonuniform flows by turbofan engines. In this work, we describe the behavior of a complex distorted inflow in a full-scale engine rig. The distortion, as in engines on a hybrid wing body (HWB) type of aircraft, is generated by a 21-in diameter StreamVane, an array of vanes that produce prescribed secondary flow distributions. Data are acquired using stereoscopic particle image velocimetry (PIV) at three measurement planes along the inlet of the research engine (Reynolds number of 2.4 × 106). A vortex dynamics-based model, named StreamFlow, is used to predict the mean secondary flow development based on the experimental data. The mean velocity profiles show that, as flow develops axially, the vortex present in the profile migrates clockwise, opposite to the rotation of the fan, and toward the spinner of the engine. The turbulent stresses indicate that the center of the vortex meanders around a preferred location, which tightens as flow gets closer to the fan, yielding a smaller radius mean vortex near the fan. Signature features of the distortion device are observed in the velocity gradients, showing the wakes generated by the distortion screen vanes in the flow. The results obtained shed light onto the aerodynamics of swirling flows representative of distorted turbofan inlets, while further advancing the understanding of the complex vane technology presented herein for advanced ground testing.

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Complex Flow Generation and Development in a Full-Scale Turbofan Inlet

Guimarães

Lowe

O’Brien

2017

Volume 2B: Turbomachinery

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The future of aviation relies on the integration of airframe and propulsion systems to increase fuel efficiency and improve the aerodynamic performance of aircraft. This need brings design challenges, such as the ingestion of non-uniform flows by turbofan engines. In this work, we seek to understand the behavior of a complex distorted inflow in a full-scale engine rig. A 21-inch diameter distortion screen previously designed is used to mimic the behavior of an adverse inlet flow encountered by a hybrid wing body type of aircraft. Three measurement planes along the inlet of the research engine are selected for the acquisition of data using particle image velocimetry at a duct diameter Reynolds number of 2.6 million. The resulting mean velocity profiles, velocity gradients and turbulent stresses are analyzed in order to describe the evolution of the flow along the inlet of the turbofan engine and as it approaches the fan face. As flow develops downstream, the vortex present in the profile migrates clockwise, opposite to the rotation of the fan, and towards the spinner of the engine. The turbulent stresses indicate that the center of the vortex meanders around a preferred location, and that location tightens as flow gets closer to the fan, yielding a smaller radius mean vortex near the fan. An analysis of velocity gradients shows the influence of the distortion screen in the flow, mainly in the streamwise direction, where signature features of the distortion device are observed, as an effect from the wakes of the vanes. The results obtained shed light onto the aerodynamics of swirling flows representative of distorted turbofan inlets, while further advancing the understanding of the complex vane technology presented herein for advanced ground testing of swirling inflows.

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Computational and Experimental Evaluation of a Complex Inlet Swirl Pattern Generation System

Cited by 12 publications

References 10 publications

Vortical flow development in round ducts across scales for engine inlet applications

Vortical flow development in round ducts across scales for engine inlet applications

Complex Flow Generation and Development in a Full-Scale Turbofan Inlet

Complex Flow Generation and Development in a Full-Scale Turbofan Inlet

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