| 1. |
- Assato, Marcelo, et al.
(författare)
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PERFORMANCE BENEFITS OF A FAN ON BLADE – FLADE – FOR A VARIABLE CYCLE ENGINE
- 2022
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Ingår i: 33th Congress of the International Council of the Aeronautical Sciences. - 2958-4647. - 9781713871163 - 9781713871163 ; 7, s. 4888-4902
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Konferensbidrag (refereegranskat)abstract
- Variable cycle engines promise to enable adaptive cycles that give close to optimal performance over a wide range of conflicting mission requirements, such as low altitude high speed flight and supercruise still providing excellent range. Modelling such engines pose challenges for general purpose software since variable geometry gas paths modify the underlying set of equations being solved. It is possible to use multiple engine models transferring design data between the models. This, however, creates a high risk for inconsistency and modelling error. It is more attractive if the solutions obtained could be determined using the same model. In this work an in-house software was developed to model an Adaptive Cycle Engine (ACE). This development was used to show how variable cycle mode switches can be integrated into general purpose performance tools. The variable cycle engine uses a FLADE, which is a "fan on blade" component, to extend its range and to provide improved subsonic performance. The individual impact of the components, its effect on propulsion performance parameters and in the engine installation were analyzed as the main results. The contribution from this paper is thus two-fold, firstly the paper goes ahead and proposes new methods for the simulation of mode switching in generic performance tools by introducing dynamic equation systems. Secondly, the paper then studies the FLADE component and its potential performance benefits if added to a conventional turbofan architecture.
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| 2. |
- Costa, Fabíola Paula, et al.
(författare)
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Coupled unsteady RANS and FW-H methodology for aeroacoustics prediction of high-speed propellers
- 2022
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Ingår i: 28th AIAA/CEAS Aeroacoustics Conference, 2022. - Reston, Virginia : American Institute of Aeronautics and Astronautics.
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Konferensbidrag (refereegranskat)abstract
- This work investigates the use of solid and permeable surfaces in the Ffowcs WilliamsHawkings (FW-H) analogy for predicting high-speed propeller noise. The CFD/CAA methodology encompasses unsteady Reynolds-Averaged Navier-Stokes simulations to compute the flowfield on the acoustic surface applied in the FWH analogy to obtain the noise signatures in the far-field. Furthermore, this manuscript also investigates the effects of the downstream end-cap position, on the propeller noise prediction, by using two permeable surfaces with different lengths to assess the propeller noise levels in each case. The former is a short SFW-H surface placed near the rotor, and the latter, namely the LFW-H, is a surface larger in length where the end-cap grid is placed farther downstream from the rotor. The results showed the capability of the permeable surface technique for predicting the noise with higher accuracy than the solid formulation, especially at the first blade passing frequency. Also, the larger LFW-H surface performed better than the SFW-H surface. A reason that could justify this is that the LFW-H end-cap surface is placed at a suitable distance downstream from the propeller. Therefore, the LFW-H surface can include more of the contributions of the non-linear effects or quadrupole sources enclosed within the permeable source surface region.
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