The inlet-vortex system of jet engines operating near the ground

Brix, Stefan Christoph Markus; Neuwerth, Günther; Jacob, Dieter

doi:10.2514/6.2000-3998

Cited by 30 publications

(30 citation statements)

References 4 publications

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“…A group of researchers from MIT [13] discussed a mechanism of formation of these vortices. Ground vortices can, however, be formed also in the absence of any ambient flow [14][15][16][17]. Yet, in both cases the flow generated by the sucked air is similar, which has been confirmed experimentally (De Siervi et al, [18]) and computationally.…”

Section: Ground Vortexmentioning

confidence: 59%

Aero-Engines Intake: A Review and Case Study

El-Sayed¹

2016

J Robot Mech Eng Resr

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This paper presents an aerodynamic review for intakes of aero-engines. Classification of different types is introduced for both subsonic and supersonic aircrafts. Important parameters influencing intake performance like pressure recovery and spillage drag are discussed. In addition, crucial performance issues such as the angle of attack, ground vortex, swirl flow, noise propagation and icing are presented. These are critical issues which are carefully considered by airframe rather than engine manufacturers. Intake icing may be extremely dangerous and leads to drastic decrease in air mass flow and consequently aircraft propulsion.Calculation of intake performance is explained. The effect of intake performance on the whole engine performance is highlighted. Numerical analyses for present and previous researches are explained and critical parameters are identified.Finally, a case study resembling the intake of a high bypass ratio turbofan engine (in close similarity to that of GE CF-6 Turbofan Engine) is numerically analysed using the commercial code "ESI-CFD 2010" is thoroughly described and analysed. This paper is the first of a series of research work that will cover several R & D activities in HBPR and future EBPR turbofan intakes.

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Section: Ground Vortexmentioning

confidence: 59%

Aero-Engines Intake: A Review and Case Study

El-Sayed¹

2016

J Robot Mech Eng Resr

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“…where normalized circulation Γ/D 2 = −55.5s −1 and vortex radius a 0 /D = 0.05. The location of the center of the vortex was chosen as 70% of the duct radius, since Brix et al [25] determined that a vortex closer to the wall would be distorted by wall interactions. The wall boundary conditions were simulated by a complementary image vortex (with opposite circulation) by adding another term to the complex velocity field, as shown in Eq.…”

Section: The Lovort Streamvane Distortion Generatormentioning

confidence: 99%

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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“…19, on the other hand, has measured the trailing vortex circulation inside the inlet and found the ground vortex much more intense than the trailing vortex. For example, Ref.…”

Section: Feeding Vortexmentioning

confidence: 99%

Evaluation of Engine Inlet Vortices Using CFD

Trapp

Girardi

2012

50th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition

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The effects of inlet vortices on engines operating near the ground have been studied for more than 50 years, but the phenomenon is not yet completely understood. Computational Fluid Dynamics (CFD) is used, on a DLR-F6 modified nacelle, to allow a more detailed look into the inlet vortices phenomenon. An updated correlation for the prediction of the ground vortex strength is shown and compared to CFD results. Additionally is presented a new technique that helps the understanding of phenomena that are highly influenced by vorticity generated on the wall. This technique is based the CFD ability to mix wall boundary conditions with and without velocity slip at the wall. Four regions on the nacelle were identified that contribute differently to the ground vortex intensity.

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The inlet-vortex system of jet engines operating near the ground

Cited by 30 publications

References 4 publications

Aero-Engines Intake: A Review and Case Study

Aero-Engines Intake: A Review and Case Study

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

Evaluation of Engine Inlet Vortices Using CFD

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